Merge origin/master into goal-ui: adopt the rewritten client core and apiproxy carrier

Conflict rulings follow the projection-reattach plan:
- host/runtime package (deleted on master): take master; the PR's boot
  composition moves to the cordis.yml roster and its goals handlers will be
  re-landed in dsh-host-apiproxy; the session.prompt slash interception and
  its spec are dropped entirely (superseded by command.execute + command/run
  logging).
- client core (rewritten on master): take master; the PR's Session goal
  fields/methods, ConversationSnapshot.goal, goalActions injection, and the
  hard-mounted GoalBar are all superseded by the 'goal' session projection
  (useProjection) and will return as the ui-goal plugin.
- wire contract: union of master's workspace/command/skill domains and the
  PR's goal domain, minus goal.get (the read side is the projection block +
  session/projection frames; six mutation RPCs stay).
- GoalBar component and spec leave ui-conversation (they re-land in the new
  ui-goal package); IconSparkle16 stays in ui-conversation chat.
- The web-slash-command-dispatch note documents the dropped interception and
  is removed; the goal-bar note will be rewritten for the projection model.
- pnpm-lock.yaml taken from master (reinstall recomputes).

packages/client/AGENTS.md

@@ -1,42 +1,62 @@
 # AGENTS.md — Web client stack
 
-Rules for `packages/client/*` (the browser side of the dsh web GUI) plus its build entry `apps/web`. They supplement the repo-wide [conventions](../../AGENTS.md#conventions) and the [package rules](../README.md); read the two architecture notes linked below before structural changes.
+Rules for `packages/client/*` (the browser side of the dsh web GUI) plus its build entry `apps/web`. They supplement the repo-wide [conventions](../../AGENTS.md#conventions) and the [package rules](../README.md). Before touching slots, component props, stores, or plugin structure, read the [slot system standard](../../.agents/notes/implemented/architecture/2026-07-22-slot-type-chain-implementation.md) (the definitive composition model) and the [web client architecture note](../../.agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.md) (loading chain, object layer, services).
 
 Packages here are named with the directory prefix: `@deepseek-ai/dsh-client-<name>`.
 
+## Slot and props discipline
+
+The [slot system standard](../../.agents/notes/implemented/architecture/2026-07-22-slot-type-chain-implementation.md) owns the full design; these are the rules you must not violate when writing or reviewing client code:
+
+1. **One API**: a plugin composes UI only through `ctx.slots.register({ name, children?, store?, inject? }, Component)`. There is no separate slot-definition call, no whitelist face object, no face-minting helper. The shell alone renders `'root'`.
+2. **children = declaration + authorization**: the slots your component renders are exactly the keys of your register call's `children` object (spec values: `kind`/`scope`). Rendering a slot you didn't declare, or declaring one someone else declared, fails at load — do not work around it; the conflict is the design speaking. Slot names mirror the composition path: `<domain>.<entry>.<hole>` (e.g. `'conversation.chat.toolview'`).
+3. **Component props are the four shares, all derived**: `PropsRuntime<K>` (SlotMap: owner params + `useSession`/`sessionId` on session scope + global `useSessions`/`useWorkspaces`) & `PropsRenderSlots<S>` (children keys) & `PropsStore<H>` (store factory) & the inject face. Never hand-write a member a share already derives; never re-type a share locally.
+4. **Hooks are framework-made only**: `useSession`, `useSessions`, `useWorkspaces`, `useStore`, `renderSlot` are the five standing seats, plus the `use<Name>` hooks the renderer binds from provide contributions and inject `hooks` compartments. Business code never creates a hook or selector as a prop value — pass plain data and callbacks. (Component-internal behavioral hooks that subscribe to nothing external are fine.)
+5. **Live data has exactly three channels**: parent knows it → owner props at the renderSlot site; only the component knows it → local state; shared across entries or survives remounts → a store declared at register. Derived data is a pure function over framework-hook data (`useMemo`), never its own subscription.
+6. **Stores: read `props.useStore`, write `props.actions.*`** — the declared actions are the complete mutation surface. Write the store as an exported `createXXXStore()` factory (module-level handles are forbidden — de-facto singletons); share by passing one handle to several registers inside `apply`. Production code never calls the factory or `.create()` outside `apply`; tests do (that is the sanctioned zero-machinery path).
+7. **inject returns plain data and callbacks** from the apply closure's own ctx — no hand-made hooks, no ReactNode producers, no whole-service objects. A registrant-private reactive fact rides the reserved `hooks` compartment (bare observables the renderer binds to `use<Name>`; components never see the sources). Its capability boundary is the plugin's declared `inject` topology; there is no wider ctx to reach for.
+
+## Reactive read and contract-currency discipline
+
+How live data reaches render code, and what may cross a business boundary:
+
+1. **Everything a render reads that can change outside React arrives through a framework hook** (rule 4 above). Event-handler code may read live snapshots (e.g. `keyboard.snapshot`); render code subscribes.
+2. **Business components contain no subscription machinery** — no `useSyncExternalStore`, no manual subscribe wiring, no mirroring an external snapshot into local state or a second store. Give each reactive fact its owning channel instead: registrant-private → the inject `hooks` compartment; cross-entry or remount-surviving → a declared store; per-session standard → `sessions.provide`.
+3. **Data-access ladder** — resolve needs in this order: framework hooks (standing seats + provide/inject-bound `use<Name>`) → a declared store (`useStore`/`actions`) → inject callbacks → anything else is a new framework seam and needs main-thread arbitration.
+4. **Contract currency is JSON-able data and callbacks.** Everything crossing a business boundary (owner props, inject faces, store state, provide contributions) is plain serializable data or a callback over such data; the inject `hooks` compartment is the one sanctioned carrier of bare observables, and components never see those either. ReactNode is not a currency: route render content through a slot; no new ReactNode-valued owner props or inject members (the composer's existing `accessory`/`overlay`/`leftItems`/`rightItems` seats are grandfathered and get migrated to slots progressively).
+5. **An observable source keeps two identities stable**: the source object itself (hook binding is cached per source), and its snapshot between changes (`getSnapshot` returns the same reference until the fact moves).
+6. **Whoever rebuilds a published value republishes it through the same source in the same step**, and a registration path that can run after consumers exist notifies the live consumers as part of registering.
+
+## Export discipline (client plugin packages)
+
+The `/client` surface of a UI plugin package is a contract face, not a convenience barrel. Three rules, enforced package-wide (do not restate them as per-file comments):
+
+1. **A UI plugin exports no values beyond what cordis loading needs** — `apply` / `inject` (and `Config` where present), plus store factories consumed type-only by components (`ReturnType<typeof createXXXStore>`). Types are the extra allowance: contract types (owner shares, injected shapes, composed props aliases) export freely. Implementation components, pure helpers, constants, and store handles stay internal. Adding any new value export requires user sign-off, not a matching consumer.
+2. **Same-package tests import internals directly** — relative `../src/client/xxx.ts` from package tests, or the `./src/*` subpath where a spec lives outside the package. Never widen the public surface to make a test compile.
+3. **Cross-package imports of another plugin's symbols are in principle forbidden.** The sanctioned routes are the slot system (register/renderSlot) and ctx services. If neither fits, stop and escalate — do not add an export to unblock yourself.
+
+## ctx discipline (components never see ctx)
+
+`ctx` belongs to the apply world only: the plugin body and the inject factories closed over it. Components — every `.tsx` under a feature domain — receive all data and callbacks **through the four props shares**; they never call a hook that reaches ctx, never import a service class to poke it, never read a React context (business components see zero contexts — `BindingContext` and its kin are renderer-internal). If a component needs something new, the answer is a prop threaded from its share's source (owner site, store declaration, or inject face), not a hook.
+
 ## Layering red lines
 
-The stack is three layers with one-way knowledge, settled in the [web client architecture note](../../.agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.md):
+The stack has one-way knowledge, settled in the [web client architecture note](../../.agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.md):
 
-1. **Data object layer** (`web-runtime`, React-free): `ConnectionController` → `SessionManager` → `Session` own all business state (event windows, streaming accumulation, reconnect machine). Zero React imports — grep-assertable.
-2. **Hooks layer** (`web-ui/src/hooks`, pure data): subscribes to object snapshots via `useSyncExternalStore`, exposes plain-data handles. No JSX, no DOM.
-3. **Presentation components** (`web-ui`, pure props): consumables, expected to be rewritten wholesale. Business logic must not leak into them; they receive data and callbacks through props only.
+1. **Data object layer** (`runtime`, React-free): `ConnectionController` → `SessionManager` → `Session` own all business state (event windows, streaming accumulation, reconnect machine), and the snapshot-store engine (zustand/immer, `defineStore`, `shallowEqual`) lives here too — store products are bare observable sources with no hook members. Zero React imports — grep-assertable.
+2. **Render machinery** (`web-react`, shell-only glue): the whole ctx↔React boundary — slot renderer/outlets, `SessionProvider`, the uSES bridge. Every hook is composed here at the binding site from bare sources; business plugin packages carry no web-react dependency at all.
+3. **Presentation components** (plugin packages' `src/client/`, pure props): consumables, expected to be rewritten wholesale. Business logic must not leak into them; everything arrives through the four props shares.
 
 Non-negotiables across the layers:
 
-- **No business objects in the store.** zustand carries cross-view presentation state only (`rpcLog`, `ui`, `connection` slices). Sessions, frames, and connections live in the object layer. View-local facts (selection, expansion) stay in component state, not the store.
+- **Business data lives in the object layer, never a store.** Entry-declared stores carry shared viewing/interaction state (selection, drafts, panel widths); sessions, frames, and connections stay in the object layer.
 - **rpcId is strictly bidirectional**: the initiator mints, the responder echoes; business signatures see only `RpcRequest<P>`, minting stays in the carrier layer ([layering and RPC protocol note](../../.agents/notes/implemented/architecture/2026-07-19-gui-layering-and-rpc-protocol.md)).
-- **Notifier dual-channel discipline**: `notifyNow` only as the direct echo of a user gesture; frame-driven updates always go through `markDirty` (microtask-batched). See `web-runtime/src/session/notifier.ts`.
+- **Notifier dual-channel discipline**: `notifyNow` only as the direct echo of a user gesture; frame-driven updates always go through `markDirty` (microtask-batched). See `runtime/src/client/sessions/notifier.ts`.
 - **The web layer is pure presentation.** Nothing that is "how to draw" (tool-card views, queue states) enters the session log; the host computes such data per frame or pushes it live, and replay recomputes it — falling back to the generic form when it can't. A new *model-visible* input still requires a session event (repo-wide rule).
 
-## Directory regime (`web-ui/src`)
+## Directory regime (plugin packages)
 
-> Shell restructure in progress: the tree is converging to this layout (today's `components/{conversation,sessions,panels}` migrate into it); the regime below is the target every new feature follows now.
-
-Two-level feature directories, one contributor per directory — physical conflict avoidance:
-
-```
-web-ui/src/
-  shell/                  # AppShell + the three slot registries + builtins
-  leftmenu/<bar>/         # one directory per left-nav bar (sessions, rpclog, …)
-  sessiontabs/<tab>/      # one directory per session tab (conversation, gantt, …)
-  components/             # shared leaves (MessageText, JsonBlock, …)
-  hooks/ utils/ style/    # cross-cutting; not feature-owned
-```
-
-- `leftmenu/<a>` must not import `leftmenu/<b>` or `sessiontabs/*` (and vice versa). Anything two features need sinks into `components/`.
-- Bars, tabs, and detail blocks register through the `shell/` registries (module-level map, `register*()` returns the disposer — same shape as `toolCardRegistry`). v1 registration is static in `shell/builtins.ts`; plugin-driven registration later calls the same functions.
-- **Claiming a placeholder slot**: pick a `placeholder: true` tab (or add a bar) in `shell/builtins.ts`, create your feature directory, and replace the placeholder component with your container. Don't build features outside this regime.
+One UI feature = one plugin package (`src/client/` browser half). A multi-domain package splits by future package boundaries — ui-conversation is the exemplar: `contract/` (the only shared face), domain directories that never import a sibling domain, and `apply.ts` as the single cross-domain assembly point; `scripts/verify-client-domain-graph.ts` enforces the levels. Registration goes through `slots.register` in `apply` — never module-level side effects.
 
 ## Styling
 
@@ -56,16 +76,26 @@ The GUI test structure (three tiers, lane map) is settled in the [GUI testing sy
 Run the narrowest rung that covers what you touched; escalate only when the change surface demands it.
 
 1. **Every GUI code change** — `pnpm run test:gui` (seconds; no browser, no server): the client suites plus the host-side GUI packages. This is the inner loop; run it as freely as a typecheck.
-2. **Changes to the build surface, boot wiring, or static serving** (`apps/web`, vite config, `dsh-host-webserver`) — additionally `pnpm run test:web`: rebuilds the frontend dist, then runs the browser smoke pair (the real-host case self-skips without `DEEPSEEK_API_KEY`).
+2. **Changes to the build surface, boot wiring, static serving, or the wire carriage** (`apps/web`, vite config, `dsh-host-webserver`, connection/handler/SSE) — additionally `pnpm run test:web`: rebuilds the frontend dist, then runs the browser smoke pair (the real-host case self-skips without `DEEPSEEK_API_KEY`) plus the keyless replayed e2e scenarios (`DSH_SNAPSHOT=refresh` rewrites their aria goldens after an intentional conversation-UI change; `DSH_SNAPSHOT=record` re-records fixtures with a key).
 3. **Before a PR** — `pnpm run check:pre-push` (the repo-wide gate ladder). Between PR windows this rung is not expected on every commit.
 
 If `test:gui` is red on code you did not touch, neither silently fix nor ignore it: note it in your handoff so it lands in the next PR window's sweep.
 
+## New plugin package checklist
+
+Bringing up a new `packages/client/<name>` plugin package (ui-workspace is the latest walked example; ui-sidebar/ui-question are good skeletons to copy):
+
+1. **Package skeleton**: `package.json` (`@deepseek-ai/dsh-client-<name>`, exports `.`/`./invariant`/`./client`/`./src/*`/`./package.json`, `dshClient` manifest, `files` list), `tsconfig.json` (extends `tsconfig.base.client.json`, one `references` entry per workspace dependency plus `support/invariants`), `tsdown.config.ts` (`clientBundle(id, ['lib/types/index.js', 'lib/types/invariant.js'])`), `src/index.ts` (empty node-half apply), `src/invariant.ts` (companion with a real reason), `src/css-modules.d.ts` when using CSS Modules, `README.md` with the Model Experience section.
+2. **Three registration surfaces, all required** (missing any one fails at a different, later point): the `tsconfig.client.json` aggregate `references` entry; a `dshClient` row in `apps/cli/cordis.yml`; an `apps/cli/package.json` dependency (Loader resolves each config-tree package against the composing app's URL — a row whose package is not an `apps/cli` dependency fails to import). `pnpm-workspace.yaml` already globs `packages/*/*`.
+3. **dshClient manifest semantics**: `platform: 'web'` always; `immediately: true` only for stage-one-prefetch infrastructure rows. `inject` lists package-name dependency edges — they are **informational only** (preflight display, HMR diffing); they do not sequence entry activation or apply order. Activation order is cordis fiber inject waiting on *services*, nothing else.
+4. **Registering into another package's slot**: if the declaring host provides no waitable service, your apply's order relative to the host's is unconstrained — a bare `slots.register` into its slot races boot (intermittent `slot "..." is not declared` page failures). Register with declaration-aware deferral: check `ctx.slots.spec(name)`, otherwise `ctx.slots.subscribe(name)` and register on the declaration event (SlotCore supports subscribing ahead of declaration); make the registration idempotent, and unsubscribe + dispose in the effect disposer. Only take a service edge in `inject` when the host actually provides one (ui-question → `'conversation'` is that case).
+5. Rebuild the bundle (`pnpm --filter <pkg> bundle`) before probing a live `dsh web` server — the registry serves `lib/client.js`, not sources.
+
 ## New component checklist
 
-1. Claim the slot (see the directory regime above): one feature, one directory.
-2. Build the container in your feature directory; keep leaves pure-props. Wire data through the hooks layer, not by importing business objects into components.
-3. Copy a neighbouring jsdom spec into `web-ui/tests/`, keep it behavior-shaped: start from the happy path and the edge states, then widen until the component's branches are covered — the coverage gate applies; only the assertion style stays behavior-level.
+1. Compose through register: merge the slot contract into `SlotMap`, declare the slot in its parent entry's `children`, register your component — see the [slot system standard](../../.agents/notes/implemented/architecture/2026-07-22-slot-type-chain-implementation.md). No other composition route exists.
+2. Type the props as the four shares (`PropsRuntime` & `PropsRenderSlots` & `PropsStore` & inject face) — derive, don't hand-write. Shared/surviving state goes in a `createXXXStore()` factory declared at register; component-private state stays local.
+3. Component tests feed props directly (`createXXXStore().create()` for the store share; plain stubs for framework hooks) — behavior-shaped assertions, no render machinery.
 4. Tokens only in CSS; Chinese product copy; English comments.
 5. `pnpm run test:gui` green (plus `test:web` if you touched the build surface).
-6. Non-trivial change? It needs an Agent Note in the same PR (repo-wide rule) — the three GUI notes above are the precedents to extend.
+6. Non-trivial change? It needs an Agent Note in the same PR (repo-wide rule) — the GUI notes above are the precedents to extend.

packages/client/connection/README.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+README.md: 80228a180faba0c556ff720e999b29b5bb1635b6
+README.zh.md: f4b857886bfafa891ceb1bd6b79b27e1fb725819

packages/client/connection/README.md

@@ -1,6 +1,12 @@
 # @deepseek-ai/dsh-client-connection
 
-Wire consumer layer (moved verbatim from web-runtime): IApiClient family (WebApiClient/FixtureApiClient), ConnectionController (SSE dual-stream + backoff reconnect), WEB_EVENTS. Contract: api-contracts v3 §3, export inventory in §3.2.
+English | [中文](README.zh.md)
+
+Wire consumer layer: the client plugin's apply mounts `ctx.connection` (shared api client + single-consumer stream-loop starter); the export face carries the wire contract types, the `AbstractApiClient` seam, and the loop's sink/config types. The platform subclasses (WebApiClient/FixtureApiClient), the ConnectionController loop, and the fixture data source are package-internal — apply selects and drives them; tests reach them via src. Contract: api-contracts v3 §3.
+
+## Keyless fixture
+
+Any `fixture` query parameter selects the in-memory carrier. `fixture=empty` starts with no Workspace or Session; `fixturePrompt=reject` rejects prompts before acceptance; `fixtureAttach=fail` publishes a Session but rejects its Workspace attachment; `fixtureSessionCreate=drop-response` publishes and frames a Session before dropping the create response; and `fixtureFrames=workspace-first` reverses the default session-first create-frame order. Workspace creation by name/path and caller-preallocated SessionIds remain deterministic enough for assembled Web tests to reconcile list and frame arrival.
 
 ## Model Experience
 

packages/client/connection/README.zh.md

@@ -0,0 +1,22 @@
+# @deepseek-ai/dsh-client-connection
+
+[English](README.md) | 中文
+
+协议消费层：客户端插件的 apply 会挂载 `ctx.connection`（共享 API 客户端 + 单消费方流循环启动器）；导出表层携带协议契约类型、`AbstractApiClient` seam，以及循环的 sink／配置类型。平台子类（WebApiClient/FixtureApiClient）、ConnectionController 循环和 fixture 数据源都属于包内部：apply 负责选择并驱动它们，测试则通过 src 访问。契约：api-contracts v3 §3。
+
+## 无密钥 fixture
+
+任何 `fixture` 查询参数都会选择内存载体。`fixture=empty` 启动时不含 Workspace 或 Session；`fixturePrompt=reject` 在接受前拒绝提示词；`fixtureAttach=fail` 发布 Session 但拒绝将其附加到 Workspace；`fixtureSessionCreate=drop-response` 在丢弃创建响应前发布 Session 并为其发出帧；`fixtureFrames=workspace-first` 则反转默认的 Session 优先创建帧顺序。按名称／路径创建 Workspace 以及由调用方预先分配 SessionId，均具有足够的确定性，组装后的 Web 测试可以据此协调列表与帧的到达。
+
+## 模型体验
+
+无。协议消费层只在浏览器与主机之间搬运已经组合好的消息；这里没有任何内容进入模型请求。
+
+#### KV Cache 影响
+
+无；该包既不组装也不发送提供方请求。
+
+## 已知限制与暂缓事项
+
+- **history 的隐式恢复存在争议**：在未附加的会话上打开 history，会在主机侧拉起 agent；纯持久化读取的替代方案记录在 rt-core 协调账本中，P-I 不作改变。该包的消费方会在首次打开时感受到这段延迟。
+- **计划移除 `ToolEventView`／`ToolCallView`／`ToolResultView` 的重新导出**：当 toolview 迁移删除主机 `viewFor` 行时，它们会一并移除（呈现属于客户端）；在此之前，fixture 保留一份局部 `viewFor` 镜像。

packages/client/connection/package.json

@@ -30,6 +30,7 @@
   "license": "BSD-3-Clause",
   "dependencies": {
     "@deepseek-ai/dsh-host-apiproxy": "workspace:^",
+    "@deepseek-ai/dsh-commands": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-tools": "workspace:^"
@@ -43,10 +44,12 @@
     "src"
   ],
   "peerDependencies": {
+    "@deepseek-ai/dsh-host-webserver": "^0.0.1",
     "@deepseek-ai/dsh-invariants": "^0.0.1",
     "cordis": "^4.0.0-rc.7"
   },
   "devDependencies": {
+    "@deepseek-ai/dsh-host-webserver": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "cordis": "^4.0.0-rc.7"
   }

packages/client/connection/src/api-path.ts

@@ -0,0 +1,8 @@
+/**
+ * The /api URL prefix — single source for both halves of the web transport.
+ * The node half registers this prefix on the web server; browser-side path
+ * literals currently live in the apiproxy client layer (out of scope here).
+ */
+
+/** Route prefix owning every api request (`/api` and `/api/<anything>`). */
+export const API_PATH = '/api'

packages/client/connection/src/client/api.ts

@@ -8,14 +8,21 @@
 export type {
   ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
   ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
-  GoalsApi, GoalView, GoalRef, GoalPhase, GoalBlockReason,
+  WorkspaceApi, WorkspaceId, WorkspaceView,
+  CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
+  ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
+  ModelReasoningEffort, ModelTarget, SessionModels,
+  GoalsApi, GoalRef,
 } from '@deepseek-ai/dsh-host-apiproxy/api'
 export type { ToolCallView, ToolResultView } from '@deepseek-ai/dsh-tools/presentation'
 export type {
   RpcRequest, RpcResponse, RpcResult, RpcError, RpcErrorCode,
   ClientRequest, ServerResponse, ServerRequest, ClientResponse, RpcMessage, RpcReceipt,
 } from '@deepseek-ai/dsh-host-apiproxy/api'
-export { RpcId } from '@deepseek-ai/dsh-host-apiproxy/api'
+// transportError moved down to the apiproxy api layer (it belongs beside
+// RpcResult, its subject); re-exported here so connection consumers keep one
+// contract entry point.
+export { RpcId, transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
 export { AbstractApiClient } from '@deepseek-ai/dsh-host-apiproxy/client'
 export type { IApiClient } from '@deepseek-ai/dsh-host-apiproxy/client'
 export type { SessionId, SessionEvent } from '@deepseek-ai/dsh-session/types'
@@ -32,16 +39,3 @@ import type { RpcResponse, RpcResult } from '@deepseek-ai/dsh-host-apiproxy/api'
 export function resultOf<T>(response: RpcResponse<T>): RpcResult<T> {
   return response.result
 }
-
-/**
- * Fold a transport exception into the RpcResult error branch (unified error
- * surface; 'internal' as the catch-all code).
- * @param error - the thrown value from the carrier.
- * @returns the error branch of an RpcResult.
- */
-export function transportError<T>(error: unknown): RpcResult<T> {
-  return {
-    ok: false,
-    error: { code: 'internal', message: error instanceof Error ? error.message : String(error), details: {} },
-  }
-}

packages/client/connection/src/client/fixture.ts

@@ -2,15 +2,34 @@
 // RpcRequest<P> and returns RpcResponse<T> (echoing the rpcId); streams yield RpcRequest<frame>
 // (the fixture IS the fake server, so it mints frame rpcIds); root respond takes ClientResponse
 // and returns RpcReceipt. fx-alpha carries a hand-built history script (60 turns, pageable);
-// prompt triggers a chunked streaming replay; cancel stops the replay; one resident pending
-// approval (placeholder-card material, subscribed-baseline-replay semantics: stable rpcId reuse).
+// prompt triggers a chunked streaming replay; cancel stops the replay; resident pending
+// approval/question requests exercise replay and composer takeover with stable rpcIds.
 
-import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
-import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
+import {
+  createAssistantMessage,
+  createToolResultMessage,
+  createUserMessage,
+} from '@deepseek-ai/dsh-llm/message'
+import { CallId } from '@deepseek-ai/dsh-llm/brand'
+import type {
+  AssistantMessage,
+  ContentBlock,
+  MessageSource,
+  ToolResultMessage,
+  UserMessage,
+} from '@deepseek-ai/dsh-llm'
+import type {
+  SessionEvent,
+  SessionId,
+  TodoItem,
+} from '@deepseek-ai/dsh-session/types'
+// Type-only: the brand constructor is host-side; the fixture casts at its
+// wire-fabrication boundary (the schema layer's one-cast-point posture).
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type {
   ApiProxy, ClientRequest, ClientResponse, HistoryEntry, HostFrame, MuxFrame, RpcReceipt,
-  RpcRequest, RpcResponse, RpcResult, ServerRequest, ServerResponse, SessionSummary,
-  ToolCallView, ToolEventView, ToolResultView, GoalView,
+  ModelTarget, RpcRequest, RpcResponse, RpcResult, ServerRequest, ServerResponse, SessionSummary,
+  ToolCallView, ToolEventView, ToolResultView, WorkspaceId, WorkspaceView,
 } from './api.ts'
 import type { RequestPayload, ResponseValue, RpcMethodMap } from '@deepseek-ai/dsh-host-apiproxy/api'
 import { AbstractApiClient, RpcId } from './api.ts'
@@ -24,6 +43,62 @@ function text(t: string): ContentBlock[] {
   return [{ type: 'text', text: t }]
 }
 
+function userMessage(content: ContentBlock[], source: MessageSource = { kind: 'user' }): UserMessage {
+  return createUserMessage({ content, source })
+}
+
+function assistantMessage(content: ContentBlock[]): AssistantMessage {
+  return createAssistantMessage({
+    content,
+    source: { provider: 'fixture', model: 'fx-1' },
+  })
+}
+
+function toolResultMessage(callId: string, content: ContentBlock[], isError: boolean): ToolResultMessage {
+  return createToolResultMessage({ callId: CallId(callId), content, isError })
+}
+
+const MARKDOWN_FIXTURE = [
+  '# Markdown fixture',
+  '',
+  'Assistant output renders **strong text**, *emphasis*, and `inline code`.',
+  '',
+  '- first item',
+  '  - nested item',
+  '',
+  '| Surface | State |',
+  '| --- | --- |',
+  '| history | rendered |',
+  '| streaming | stable |',
+  '',
+  '[DeepSeek](https://www.deepseek.com)',
+  '',
+  '```ts',
+  'const markdown = true',
+  '```',
+].join('\n')
+
+const USER_MARKDOWN_LITERAL = '用户字面量：# 不渲染 `code` [link](https://example.com)'
+
+const DEEPSEEK_REASONING = {
+  efforts: [
+    { id: 'off', name: 'Off' },
+    { id: 'high', name: 'High' },
+    { id: 'max', name: 'Max' },
+  ],
+  defaultEffort: 'high',
+}
+
+const OPENAI_REASONING = {
+  efforts: [
+    { id: 'off', name: 'Off' },
+    { id: 'medium', name: 'Medium' },
+    { id: 'high', name: 'High' },
+    { id: 'max', name: 'Max' },
+  ],
+  defaultEffort: 'medium',
+}
+
 function sid(id: string): SessionId {
   return id as SessionId
 }
@@ -40,54 +115,124 @@ function buildAlphaLog(): SessionEvent[] {
   }
   for (let turn = 0; turn < 60; turn++) {
     push({ type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
-    push({ type: 'user/message', surfaceOp: 'append', data: { content: text(`问题 ${turn}：fixture 历史消息，用于翻页与渲染验收。`), source: { kind: 'user' } } })
+    const userSeq = push({
+      type: 'user/message', surfaceOp: 'append',
+      data: userMessage(text(turn === 59 ? USER_MARKDOWN_LITERAL : `问题 ${turn}：fixture 历史消息，用于翻页与渲染验收。`)),
+    })
+    if (turn === 0) {
+      push({
+        type: 'session/title',
+        data: { title: 'Fixture 历史会话', messageSeqs: [userSeq], source: { kind: 'fallback' } },
+      })
+    }
     if (turn % 9 === 4) {
-      push({ type: 'context/message', surfaceOp: 'append', data: { content: text(`[fixture] 上下文注入（turn ${turn}）`), source: { kind: 'plugin', plugin: 'fixture' } } })
+      push({ type: 'user/message', surfaceOp: 'append', data: userMessage(text(`[fixture] 上下文注入（turn ${turn}）`), { kind: 'plugin', plugin: 'fixture' }) })
     }
     push({ type: 'step/start', data: { turn, step: 0 } })
     const withTool = turn % 5 === 2
     const withReasoning = turn % 3 === 1
     const blocks: ContentBlock[] = []
     if (withReasoning) blocks.push({ type: 'reasoning', text: `思考过程 ${turn}：这是一段可折叠的 reasoning 内容。` })
-    blocks.push({ type: 'text', text: `回答 ${turn}：这是 fixture 生成的历史回复正文。` })
+    blocks.push({ type: 'text', text: turn === 59 ? MARKDOWN_FIXTURE : `回答 ${turn}：这是 fixture 生成的历史回复正文。` })
     if (withTool) {
       const callId = `fx-call-${turn}`
       blocks.push({ type: 'tool-call', id: callId, name: 'echo', arguments: `{"text":"turn ${turn}"}` } as ContentBlock)
-      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 0, content: blocks, provenance: { provider: 'fixture', model: 'fx-1' } } })
+      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 0, message: assistantMessage(blocks) } })
       push({ type: 'tool/call', data: { turn, step: 0, callId, name: 'echo', arguments: `{"text":"turn ${turn}"}` } })
-      push({ type: 'tool/result', surfaceOp: 'append', data: { turn, step: 0, callId, content: text(`ECHO: TURN ${turn}`), isError: turn % 25 === 12 } })
+      push({ type: 'tool/result', surfaceOp: 'append', data: { turn, step: 0, message: toolResultMessage(callId, text(`ECHO: TURN ${turn}`), turn % 25 === 12) } })
       push({ type: 'step/end', data: { turn, step: 0 } })
       push({ type: 'step/start', data: { turn, step: 1 } })
-      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 1, content: text(`工具结果已消化（turn ${turn}）。`), provenance: { provider: 'fixture', model: 'fx-1' } } })
+      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 1, message: assistantMessage(text(`工具结果已消化（turn ${turn}）。`)) } })
       push({ type: 'step/end', data: { turn, step: 1 } })
     } else {
-      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 0, content: blocks, provenance: { provider: 'fixture', model: 'fx-1' } } })
+      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 0, message: assistantMessage(blocks) } })
       push({ type: 'step/end', data: { turn, step: 0 } })
     }
     if (turn % 13 === 6) {
-      push({ type: 'steering/message', surfaceOp: 'append', data: { turn, content: text(`插话 ${turn}：fixture steering 消息。`), source: { kind: 'user' } } })
+      push({ type: 'steering/message', surfaceOp: 'append', data: { turn, message: userMessage(text(`插话 ${turn}：fixture steering 消息。`)) } })
     }
     push({ type: 'turn/end', data: { turn, reason: { kind: 'completed' } } })
   }
-  // Three view-sample turns (60-62) for the tool-card wire acceptance: one per built-in card
-  // type. `echo` above stays presenter-less on purpose — it is the no-view fallback sample.
+  // Three view-sample turns (60-62) cover the built-in card types. The real filesystem names in
+  // turns 62-63 also exercise their dedicated generic-row icon/title/path summaries. `echo` above
+  // stays presenter-less as the unknown fallback.
   const toolTurn = (turn: number, name: string, args: string, resultText: string): void => {
     const callId = `fx-call-${turn}`
     push({ type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
-    push({ type: 'user/message', surfaceOp: 'append', data: { content: text(`问题 ${turn}：${name} 样本。`), source: { kind: 'user' } } })
+    push({ type: 'user/message', surfaceOp: 'append', data: userMessage(text(`问题 ${turn}：${name} 样本。`)) })
     push({ type: 'step/start', data: { turn, step: 0 } })
     push({
       type: 'assistant/message', surfaceOp: 'append',
-      data: { turn, step: 0, content: [{ type: 'tool-call', id: callId, name, arguments: args } as ContentBlock], provenance: { provider: 'fixture', model: 'fx-1' } },
+      data: { turn, step: 0, message: assistantMessage([{ type: 'tool-call', id: callId, name, arguments: args } as ContentBlock]) },
     })
     push({ type: 'tool/call', data: { turn, step: 0, callId, name, arguments: args } })
-    push({ type: 'tool/result', surfaceOp: 'append', data: { turn, step: 0, callId, content: text(resultText), isError: false } })
+    push({ type: 'tool/result', surfaceOp: 'append', data: { turn, step: 0, message: toolResultMessage(callId, text(resultText), false) } })
     push({ type: 'step/end', data: { turn, step: 0 } })
     push({ type: 'turn/end', data: { turn, reason: { kind: 'completed' } } })
   }
   toolTurn(60, 'fx-bash', '{"command":"ls -la","cwd":"/tmp/fixture"}', 'total 2\ndrwxr-xr-x fixture\n-rw-r--r-- demo.txt')
   toolTurn(61, 'fx-write', '{"path":"notes/demo.txt","content":"hello fixture\\n"}', 'wrote notes/demo.txt')
-  toolTurn(62, 'fx-note', '{"note":"三型卡验收样本"}', '已记录')
+  toolTurn(62, 'edit', '{"file_path":"notes/demo.txt","old_string":"hello","new_string":"hello fixture"}', '已编辑')
+  toolTurn(63, 'write', '{"file_path":"notes/new-demo.txt","content":"hello fixture\\n"}', '已写入')
+  // Turn 64: one run_code turn with three logged sub-dispatches — the Code
+  // Mode acceptance surface (parent code row + nested native-identical rows,
+  // including an isError sub-call and a bash sub-call that must hit the same
+  // keyed registration a top-level bash row uses).
+  {
+    const turn = 64
+    const callId = `fx-call-${turn}`
+    const program = 'const listing = await tools.bash({ command: "ls notes", description: "List notes" })\n'
+      + 'const demo = await tools.read({ path: "notes/demo.txt" })\n'
+      + 'await tools.read({ path: "notes/missing.txt" }).catch(() => "tolerated")\n'
+      + 'return { listing, demo }'
+    const args = JSON.stringify({ code: program, description: 'Read the notes files and summarize' })
+    push({ type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
+    push({ type: 'user/message', surfaceOp: 'append', data: userMessage(text(`问题 ${turn}：run_code 样本。`)) })
+    push({ type: 'step/start', data: { turn, step: 0 } })
+    push({
+      type: 'assistant/message', surfaceOp: 'append',
+      data: { turn, step: 0, message: assistantMessage([{ type: 'tool-call', id: callId, name: 'run_code', arguments: args } as ContentBlock]) },
+    })
+    push({ type: 'tool/call', data: { turn, step: 0, callId, name: 'run_code', arguments: args } })
+    const dispatchPair = (n: number, name: string, dispatchArgs: Record<string, unknown>, resultText: string, isError = false): void => {
+      push({
+        type: 'tool/code-dispatch-start',
+        data: { parentCallId: callId, subCallId: `${callId}:code:${n}`, name, arguments: dispatchArgs },
+      })
+      push({
+        type: 'tool/code-dispatch',
+        data: {
+          parentCallId: callId, subCallId: `${callId}:code:${n}`, name,
+          arguments: dispatchArgs, isError, content: [{ type: 'text', text: resultText }],
+        },
+      })
+    }
+    dispatchPair(1, 'bash', { command: 'ls notes', description: 'List notes' }, 'demo.txt\nnew-demo.txt')
+    dispatchPair(2, 'read', { path: 'notes/demo.txt' }, 'hello fixture\n')
+    dispatchPair(3, 'read', { path: 'notes/missing.txt' }, 'Error: ENOENT: notes/missing.txt not found', true)
+    push({
+      type: 'tool/result', surfaceOp: 'append',
+      data: { turn, step: 0, message: toolResultMessage(callId, text('{"listing":"demo.txt\\nnew-demo.txt","demo":"hello fixture\\n"}'), false) },
+    })
+    push({ type: 'step/end', data: { turn, step: 0 } })
+    push({ type: 'turn/end', data: { turn, reason: { kind: 'completed' } } })
+  }
+  // Turn 65: todo_write sample — the TodoRow toolview in the flow plus the
+  // todo/write snapshot event feeding the TodoPanel plan strip.
+  const fixtureTodos = [
+    { content: '梳理需求', status: 'completed' },
+    { content: '实现 fixture 样本', status: 'in_progress' },
+    { content: '浏览器验收', status: 'pending' },
+  ]
+  const todoArgs = JSON.stringify({ todos: fixtureTodos })
+  toolTurn(65, 'todo_write', todoArgs, 'Updated todo list: 1 pending, 1 in progress, 1 completed.')
+  // The real tool appends the snapshot mid-execution — between tool/call and
+  // tool/result — so the fixture reproduces that exact ordering (the last
+  // toolTurn events run ... tool/call, tool/result, step/end, turn/end).
+  const callIndex = events.length - 4
+  const callTime = events[callIndex]?.time as number
+  events.splice(callIndex + 1, 0, { type: 'todo/write', time: callTime + 400, data: { todos: fixtureTodos } })
+  events.forEach((e, i) => { e.seq = i })
   return events as unknown as SessionEvent[]
 }
 
@@ -112,8 +257,10 @@ function presentCall(name: string, argsRaw: string): ToolCallView | undefined {
         card: 'diff', title: `Write ${str(args.path)}`,
         diffs: [{ path: str(args.path), oldText: null, newText: str(args.content) }],
       }
-    case 'fx-note':
-      return { card: 'generic', title: '记录笔记', kind: 'edit', rawInput: args }
+    case 'edit':
+      return { card: 'generic', title: `Edit ${str(args.file_path)}`, kind: 'edit', rawInput: args }
+    case 'write':
+      return { card: 'generic', title: `Write ${str(args.file_path)}`, kind: 'edit', rawInput: args }
     default:
       return undefined // echo et al: the documented no-view fallback path
   }
@@ -139,13 +286,13 @@ function viewFor(event: SessionEvent, log: readonly SessionEvent[]): ToolEventVi
     return view === undefined ? undefined : { for: 'call', view }
   }
   if (event.type === 'tool/result') {
-    const callId = String(event.data.callId)
+    const callId = String(event.data.message.source.callId)
     for (let i = log.length - 1; i >= 0; i--) {
       const candidate = log[i]
       /* v8 ignore next -- dense-array guard: i stays within [0, log.length),
       so the undefined arm needs a sparse log no code path builds. */
       if (candidate !== undefined && candidate.type === 'tool/call' && String(candidate.data.callId) === callId) {
-        const resultText = event.data.content.map(b => (b.type === 'text' ? b.text : '')).join('')
+        const resultText = event.data.message.content[0].content.map(b => (b.type === 'text' ? b.text : '')).join('')
         const view = presentResult(candidate.data.name, candidate.data.arguments, resultText)
         return view === undefined ? undefined : { for: 'result', view }
       }
@@ -155,6 +302,40 @@ function viewFor(event: SessionEvent, log: readonly SessionEvent[]): ToolEventVi
   return undefined
 }
 
+/** Fixture parallel of the host's projection units: whole current values per key over the full log. */
+function projectionValuesOf(log: readonly SessionEvent[]): Record<string, unknown> {
+  const values: Record<string, unknown> = {}
+  const titleEvent = log.findLast(item => (item as { type: string }).type === 'session/title')
+  if (titleEvent !== undefined) {
+    values['title'] = (titleEvent as unknown as { data: { title: string } }).data.title
+  }
+  // Always present (tool-todo unit composed): null when no plan stands.
+  values['todos'] = backscanTodos(log) ?? null
+  return values
+}
+
+/** Host push-frame parallel: emit one session/projection frame per key the given event advanced. */
+function projectionFramesOf(id: SessionId, log: readonly SessionEvent[], event: SessionEvent): Extract<MuxFrame, { type: 'session/projection' }>[] {
+  const type = (event as { type: string }).type
+  if (type === 'session/title') {
+    const values = projectionValuesOf(log)
+    /* v8 ignore next -- the advancing title event is in the log, so the key is present. */
+    if (!Object.hasOwn(values, 'title')) return []
+    return [{ type: 'session/projection', sessionId: id, key: 'title', value: values['title'], seq: event.seq }]
+  }
+  // Standing-plan fold: writes replace the list; turn/start clears it (null).
+  if (type === 'todo/write' || type === 'turn/start') {
+    return [{
+      type: 'session/projection',
+      sessionId: id,
+      key: 'todos',
+      value: backscanTodos(log) ?? null,
+      seq: event.seq,
+    }]
+  }
+  return []
+}
+
 /**
  * Message-boundary paging (mirrors the host's paging contract): count
  * maxMessages messages
@@ -186,10 +367,38 @@ function pageOf(
   return { events, hasMore: start > 0 }
 }
 
+/**
+ * Current plan projection over the full log (host parallel: latest todo/write
+ * with no later turn/start; a new turn retires the previous plan).
+ */
+function backscanTodos(log: readonly SessionEvent[]): TodoItem[] | undefined {
+  for (let i = log.length - 1; i >= 0; i--) {
+    const event = log[i]
+    if (event === undefined) continue
+    if (event.type === 'turn/start') return undefined
+    if (event.type === 'todo/write') return event.data.todos
+  }
+  return undefined
+}
+
 interface StreamConn<F> {
   push(envelope: RpcRequest<F>): void
 }
 
+/** Deterministic fixture branches used by keyless Web assembly tests. */
+export interface FixtureOptions {
+  /** Start with no real Workspace or Session. */
+  empty?: boolean
+  /** Reject every prompt before appending its user event. */
+  rejectPrompt?: boolean
+  /** Publish the Session but fail its Workspace account write. */
+  failWorkspaceAttach?: boolean
+  /** Publish and frame the Session, then throw instead of returning create. */
+  dropSessionCreateResponse?: boolean
+  /** Order of the two successful create frames. */
+  createFrameOrder?: 'session-first' | 'workspace-first'
+}
+
 /** Inbox pump shared by both stream generators (FrameQueue pattern: ONE abort listener hung
  *  outside the loop — a per-iteration {once:true} listener never fires for non-final rounds and
  *  piles up for the stream's lifetime, audit C5). breakNow force-ends the stream without the
@@ -234,26 +443,76 @@ class FxInbox<F> implements StreamConn<F> {
 
 /**
  * In-memory fake host: fx-alpha carries history and replay scripts; fx-beta is fx-alpha's child session (lineage indent material).
+ * @param options - fixture branches for empty state and failure timing.
  * @returns an ApiProxy backed entirely by in-memory state — no host process, no network.
  */
-export function createFixtureApi(): ApiProxy {
-  const sessions: SessionSummary[] = [
-    { sessionId: sid('fx-alpha'), updatedAt: Date.now(), running: true, cwd: '/tmp/fixture' },
-    { sessionId: sid('fx-beta'), updatedAt: Date.now() - 60_000, running: false, parentSessionId: sid('fx-alpha'), cwd: '/tmp/fixture' },
-    { sessionId: sid('fx-gamma'), updatedAt: Date.now() - 120_000, running: false, cwd: '/tmp/fixture' },
+export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
+  // The resident fixture sessions all carry history, so none of them is blank.
+  const sessions: SessionSummary[] = options.empty ? [] : [
+    { sessionId: sid('fx-alpha'), updatedAt: Date.now(), running: true, blank: false, cwd: '/tmp/fixture' },
+    { sessionId: sid('fx-beta'), updatedAt: Date.now() - 60_000, running: false, blank: false, parentSessionId: sid('fx-alpha'), cwd: '/tmp/fixture' },
+    { sessionId: sid('fx-gamma'), updatedAt: Date.now() - 120_000, running: false, blank: false, cwd: '/tmp/fixture' },
   ]
   const logs = new Map<SessionId, SessionEvent[]>([[sid('fx-alpha'), buildAlphaLog()]])
-  const fixtureGoal: GoalView = {
-    id: 'fx-goal-1' as GoalView['id'], revision: 1, objective: 'Ship the fixture goal bar',
-    phase: 'active', maxGoalRounds: 4, roundsStarted: 1, createdAt: 1, updatedAt: 2,
-    activation: 'armed',
-  }
+  const modelTargets = new Map<SessionId, ModelTarget>(sessions.map(session => [
+    session.sessionId,
+    { provider: 'deepseek', model: 'deepseek-v4-flash' },
+  ]))
   const nextTurn = new Map<SessionId, number>([[sid('fx-alpha'), 60]])
   let nextSession = 1
   let nextRpc = 1
+  let attachedSessions = options.empty ? 0 : 1
+  // Workspace entities mirroring the host registry: the fixture sessions all
+  // live under one workspace, whose account carries them in attach order.
+  const wid = (raw: string): WorkspaceId => raw as WorkspaceId
+  const fixtureEpoch = new Date(Date.now() - 300_000).toISOString()
+  const workspaces: WorkspaceView[] = options.empty ? [] : [{
+    workspaceId: wid('fx-ws-fixture'),
+    path: '/tmp/fixture',
+    title: 'fixture',
+    sessionIds: [sid('fx-alpha'), sid('fx-beta'), sid('fx-gamma')],
+    createdAt: fixtureEpoch,
+    updatedAt: fixtureEpoch,
+  }]
+  let nextWorkspace = 1
   const mint = (): ReturnType<typeof RpcId> => RpcId(`fx-rpc-${nextRpc++}`)
   /** Resident pending approval (stable rpcId: every mux open replays the same id, matching host replay semantics). */
   const pendingApprovalRpcId = mint()
+  const pendingQuestionRpcId = mint()
+  let questionPending = true
+  const fixtureQuestions: Extract<MuxFrame, { type: 'question/requested' }>['questions'] = [
+    {
+      id: 'harness-profile',
+      header: '偏好',
+      question: '你现在更想招哪类 Agent/Harness 候选人？',
+      options: [
+        { label: '工程落地型 (Recommended)', description: '更看重能直接做 runtime、tool executor、sandbox、trace 和线上问题排查。' },
+        { label: '研究潜力型', description: '更看重 Agent 理解、训练评测思路和长期成长空间。' },
+        { label: '均衡型', description: '同时要求工程能力和 Agent 认知，但可能筛选门槛更高。' },
+      ],
+    },
+    {
+      id: 'work-mode',
+      header: '方式',
+      question: '你希望候选人优先展示哪种工作方式？',
+      options: [
+        { label: '先做小型原型 (Recommended)', description: '用可运行结果尽快验证关键假设。' },
+        { label: '先写完整设计', description: '先收敛边界、协议和风险，再开始实现。' },
+      ],
+    },
+    {
+      id: 'signals',
+      header: '信号',
+      question: '哪些面试信号最重要？',
+      detail: '按当前招聘目标选择；跳过则视为不设偏好。',
+      multiSelect: true,
+      options: [
+        { label: '系统设计' },
+        { label: '代码质量' },
+        { label: 'Agent 产品判断' },
+      ],
+    },
+  ]
 
   const muxConns = new Set<StreamConn<MuxFrame>>()
   const hostConns = new Set<StreamConn<HostFrame>>()
@@ -273,6 +532,16 @@ export function createFixtureApi(): ApiProxy {
   }
 
   const summaryOf = (id: SessionId): SessionSummary | undefined => sessions.find(s => s.sessionId === id)
+  /** Shared session guard for sessionId-addressed catalog routes: the error
+   *  response when the session is unknown, undefined when it exists. */
+  const requireSession = (request: RpcRequest<{ sessionId: SessionId }>): Promise<RpcResponse<never>> | undefined => {
+    if (summaryOf(request.payload.sessionId) !== undefined) return undefined
+    return err<{ sessionId: SessionId }, never>(request, {
+      code: 'session-not-found',
+      message: `no session ${request.payload.sessionId}`,
+      details: { sessionId: request.payload.sessionId },
+    })
+  }
   const setRunning = (id: SessionId, running: boolean): void => {
     const summary = summaryOf(id)
     if (summary === undefined || summary.running === running) return
@@ -299,6 +568,8 @@ export function createFixtureApi(): ApiProxy {
     emitMux(view === undefined
       ? { type: 'session/event', sessionId: id, event }
       : { type: 'session/event', sessionId: id, event, view })
+    // Host eager-drive parallel: a unit-advancing event pushes its finished value.
+    for (const frame of projectionFramesOf(id, log, event)) emitMux(frame)
   }
 
   /** At most one in-flight replay per session; cancel clears it. */
@@ -325,12 +596,18 @@ export function createFixtureApi(): ApiProxy {
     },
     /** Log append + mux emit (the normal live path). */
     appendUser(id: string, msg: string): void {
-      append(sid(id), { type: 'user/message', surfaceOp: 'append', data: { content: text(msg), source: { kind: 'user' } } })
+      append(sid(id), { type: 'user/message', surfaceOp: 'append', data: userMessage(text(msg)) })
+    },
+    /** Append a later durable title revision through the normal raw-event + control-frame path. */
+    appendTitle(id: string, title: string): void {
+      const log = logOf(sid(id))
+      const messageSeqs = log.filter(event => event.type === 'user/message').map(event => event.seq)
+      append(sid(id), { type: 'session/title', data: { title, messageSeqs, source: { kind: 'provider', provider: 'fixture' } } })
     },
     /** Log append WITHOUT the mux emit: a frame lost in transit — history still serves it, the client must repull. */
     appendSilent(id: string, msg: string): void {
       const log = logOf(sid(id))
-      log.push({ type: 'user/message', surfaceOp: 'append', seq: log.length, time: Date.now(), data: { content: text(msg), source: { kind: 'user' } } } as unknown as SessionEvent)
+      log.push({ type: 'user/message', surfaceOp: 'append', seq: log.length, time: Date.now(), data: userMessage(text(msg)) } as unknown as SessionEvent)
     },
     /** End every open stream generator (client sees both streams close -> reconnect + resync path). */
     breakStreams(): void {
@@ -344,14 +621,14 @@ export function createFixtureApi(): ApiProxy {
     const step = 0
     append(id, { type: 'step/start', data: { turn, step } })
     append(id, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'block-start', index: 0, blockType: 'text' } } })
-    /* v8 ignore next -- the ?? arm needs a null match, but replyText is never empty (prompt always prefixes 回声). */
-    const pieces = replyText.match(/.{1,6}/gu) ?? [replyText]
+    /* v8 ignore next -- the ?? arm needs a null match, but every fixture reply is non-empty. */
+    const pieces = replyText.match(/[\s\S]{1,6}/gu) ?? [replyText]
     let i = 0
     const finish = (aborted: boolean): void => {
       replays.delete(id)
       const done = pieces.slice(0, i).join('')
       append(id, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'block-end', index: 0, block: { type: 'text', text: done } } } })
-      append(id, { type: 'assistant/message', surfaceOp: 'append', data: { turn, step, content: text(aborted ? `${done}（已中断）` : done), provenance: { provider: 'fixture', model: 'fx-1' } } })
+      append(id, { type: 'assistant/message', surfaceOp: 'append', data: { turn, step, message: assistantMessage(text(aborted ? `${done}（已中断）` : done)) } })
       append(id, { type: 'step/end', data: { turn, step } })
       append(id, { type: 'turn/end', data: { turn, reason: { kind: aborted ? 'cancelled' : 'completed' } } })
       setRunning(id, false)
@@ -372,24 +649,132 @@ export function createFixtureApi(): ApiProxy {
   return {
     sessions: {
       list: request => ok(request, { items: [...sessions].sort((a, b) => b.updatedAt - a.updatedAt) }),
-      create: (request) => {
+      create: async (request) => {
+        const workspace = request.payload.workspaceId === undefined
+          ? undefined
+          : workspaces.find(w => w.workspaceId === request.payload.workspaceId)
+        if (request.payload.workspaceId !== undefined && workspace === undefined) {
+          return err(request, {
+            code: 'workspace-not-found',
+            message: `no workspace ${request.payload.workspaceId}`,
+            details: { workspaceId: request.payload.workspaceId },
+          })
+        }
+        const cwd = workspace?.path ?? request.payload.cwd ?? '/tmp/fixture'
+        const requestedId = request.payload.sessionId
+        const attachWorkspace = (sessionId: SessionId): void => {
+          /* v8 ignore next -- callers enter only when a target Workspace exists. */
+          if (workspace === undefined || workspace.sessionIds.includes(sessionId)) return
+          workspace.sessionIds = [sessionId, ...workspace.sessionIds]
+          workspace.updatedAt = new Date().toISOString()
+          emitHost({ type: 'host/workspace-changed', workspace: { ...workspace } })
+        }
+        const attachFailure = (
+          sessionId: SessionId,
+          workspaceId: WorkspaceId,
+        ): Promise<RpcResponse<{ sessionId: SessionId }>> => err(request, {
+          code: 'workspace-attach-failed' as const,
+          message: `fixture rejected Workspace attachment for ${sessionId}`,
+          details: { sessionId, workspaceId },
+        })
+        if (requestedId !== undefined) {
+          const existing = summaryOf(requestedId)
+          if (existing !== undefined) {
+            if (existing.cwd !== cwd) {
+              return err(request, {
+                code: 'session-conflict',
+                message: `session ${requestedId} already uses ${existing.cwd ?? 'no cwd'}`,
+                details: { sessionId: requestedId, requestedCwd: cwd, ...existing.cwd === undefined ? {} : { existingCwd: existing.cwd } },
+              })
+            }
+            if (workspace !== undefined && !workspace.sessionIds.includes(requestedId)) {
+              if (options.failWorkspaceAttach) return attachFailure(requestedId, workspace.workspaceId)
+              attachWorkspace(requestedId)
+            }
+            return ok(request, { sessionId: requestedId })
+          }
+        }
         const created: SessionSummary = {
-          sessionId: sid(`fx-${nextSession++}`), updatedAt: Date.now(), running: false, cwd: '/tmp/fixture',
+          sessionId: requestedId ?? sid(`fx-${nextSession++}`), updatedAt: Date.now(), running: false, blank: true, cwd,
         }
         sessions.push(created)
-        emitHost({ type: 'host/session-added', sessionId: created.sessionId })
+        modelTargets.set(created.sessionId, { provider: 'deepseek', model: 'deepseek-v4-flash' })
+        attachedSessions += 1
+        const emitSession = (): void => {
+          // Mirrors the host: the frame fires at creation, so blank is constantly true.
+          emitHost({ type: 'host/session-added', sessionId: created.sessionId, blank: true, cwd })
+        }
+        if (workspace !== undefined && options.failWorkspaceAttach) {
+          emitSession()
+          return attachFailure(created.sessionId, workspace.workspaceId)
+        }
+        if (workspace !== undefined && options.createFrameOrder === 'workspace-first') {
+          attachWorkspace(created.sessionId)
+          emitSession()
+        } else {
+          emitSession()
+          if (workspace !== undefined) attachWorkspace(created.sessionId)
+        }
+        if (options.dropSessionCreateResponse) throw new Error('fixture: dropped session.create response after publication')
         return ok(request, { sessionId: created.sessionId })
       },
       history: async (request) => {
         const log = logs.get(request.payload.sessionId) ?? []
         // Snapshot at request time, deliver after the transit delay (mirrors a real host under latency).
         const page = pageOf(log, request.payload.beforeSeq, request.payload.maxMessages ?? 50)
+        // Tail page carries the projections block (host parallel: one consistent
+        // cut over the registered units; asOfSeq = window tail seq, -1 on an
+        // empty log — the host's session.seq-1 convention).
+        const projections = request.payload.beforeSeq === undefined
+          ? { asOfSeq: log.length - 1, values: projectionValuesOf(log) }
+          : undefined
         const doomed = failNextHistory
         failNextHistory = false
         const delay = historyDelayMs
         if (delay > 0) await new Promise(resolve => setTimeout(resolve, delay))
         if (doomed) throw new Error('fixture: simulated history transport failure')
-        return ok(request, page)
+        return ok(request, { ...page, ...projections === undefined ? {} : { projections } })
+      },
+      models: request => ok(request, {
+        current: modelTargets.get(request.payload.sessionId)
+          ?? { provider: 'deepseek', model: 'deepseek-v4-flash' },
+        groups: [
+          {
+            id: 'deepseek',
+            name: 'DeepSeek',
+            models: [
+              {
+                id: 'deepseek-v4-flash',
+                name: 'DeepSeek-V4-Flash',
+                description: '快速响应',
+                reasoning: DEEPSEEK_REASONING,
+              },
+              {
+                id: 'deepseek-v4-pro',
+                name: 'DeepSeek-V4-Pro',
+                description: '复杂任务',
+                reasoning: DEEPSEEK_REASONING,
+              },
+            ],
+          },
+          {
+            id: 'openai',
+            name: 'OpenAI',
+            models: [{ id: 'gpt-5', name: 'GPT-5', reasoning: OPENAI_REASONING }],
+          },
+        ],
+        failures: [],
+      }),
+      selectModel: (request) => {
+        const selected: ModelTarget = {
+          provider: request.payload.provider,
+          model: request.payload.model,
+          ...request.payload.reasoningEffort === undefined
+            ? {}
+            : { reasoningEffort: request.payload.reasoningEffort },
+        }
+        modelTargets.set(request.payload.sessionId, selected)
+        return ok(request, { selected })
       },
       prompt: (request) => {
         const { sessionId: id, mode, content } = request.payload
@@ -397,21 +782,42 @@ export function createFixtureApi(): ApiProxy {
         if (summary === undefined) {
           return err(request, { code: 'session-not-found', message: `no session ${id}`, details: { sessionId: id } })
         }
+        if (options.rejectPrompt) {
+          return err(request, {
+            code: 'agent-busy',
+            message: 'fixture: prompt rejected before acceptance',
+            details: { reason: 'fixture-prompt-rejection' },
+          })
+        }
         summary.updatedAt = Date.now()
+        // First accepted prompt appends events: the summary stops being blank.
+        summary.blank = false
         const userText = content.map(b => (b.type === 'text' ? b.text : '')).join('')
         if (mode === 'steer' && replays.has(id)) {
           // Steering: insert a steering message into the current turn; the replay continues.
           /* v8 ignore next -- the ?? arm needs a missing counter, but a live replay implies a prior prompt already set it. */
           const turn = (nextTurn.get(id) ?? 1) - 1
-          append(id, { type: 'steering/message', surfaceOp: 'append', data: { turn, content, source: { kind: 'user' } } })
+          append(id, { type: 'steering/message', surfaceOp: 'append', data: { turn, message: userMessage(content) } })
           return ok(request, { accepted: true as const })
         }
         const turn = nextTurn.get(id) ?? 0
         nextTurn.set(id, turn + 1)
         setRunning(id, true)
         append(id, { type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
-        append(id, { type: 'user/message', surfaceOp: 'append', data: { content, source: { kind: 'user' } } })
-        startReply(id, turn, `回声：${userText}。这是 fixture 的流式回复，用于验证打字机增长与定稿切换。`)
+        append(id, { type: 'user/message', surfaceOp: 'append', data: userMessage(content) })
+        startReply(
+          id,
+          turn,
+          userText === 'render markdown'
+            ? MARKDOWN_FIXTURE
+            : userText === 'report model'
+              ? (() => {
+                const target = modelTargets.get(id)
+                return `当前模型：${target?.provider ?? 'unknown'}/${target?.model ?? 'unknown'}`
+                  + (target?.reasoningEffort === undefined ? '' : ` · 推理等级：${target.reasoningEffort}`)
+              })()
+              : `回声：${userText}。这是 fixture 的流式回复，用于验证打字机增长与定稿切换。`,
+        )
         return ok(request, { accepted: true as const })
       },
       cancel: (request) => {
@@ -426,10 +832,149 @@ export function createFixtureApi(): ApiProxy {
       },
     },
     host: {
-      describe: request => ok(request, { version: '0.0.0-fixture', cwd: '/tmp/fixture', attachedSessions: 1 }),
+      describe: request => ok(request, { version: '0.0.0-fixture', cwd: '/tmp/fixture', attachedSessions }),
+      pickDirectory: request => ok(request, { path: null }),
+      openPath: request => ok(request, { opened: true as const }),
+    },
+    workspace: {
+      list: request => ok(request, { items: workspaces.map(w => ({ ...w })) }),
+      create: (request) => {
+        const { path, name } = request.payload
+        const target = path ?? `/tmp/fixture-workspaces/${name ?? ''}`
+        const existing = workspaces.find(w => w.path === target)
+        if (existing !== undefined) return ok(request, { workspace: { ...existing }, created: false })
+        const now = new Date().toISOString()
+        const created: WorkspaceView = {
+          workspaceId: wid(`fx-ws-${nextWorkspace++}`),
+          path: target,
+          title: name ?? target.split('/').filter(Boolean).at(-1) ?? target,
+          sessionIds: [],
+          createdAt: now,
+          updatedAt: now,
+        }
+        workspaces.unshift(created)
+        emitHost({ type: 'host/workspace-changed', workspace: { ...created } })
+        return ok(request, { workspace: { ...created }, created: true })
+      },
+      rename: (request) => {
+        const { workspaceId, title } = request.payload
+        const workspace = workspaces.find(w => w.workspaceId === workspaceId)
+        if (workspace === undefined) {
+          return err(request, {
+            code: 'workspace-not-found',
+            message: `no workspace ${workspaceId}`,
+            details: { workspaceId },
+          })
+        }
+        const trimmed = title.trim()
+        if (trimmed !== workspace.title) {
+          if (workspaces.some(w => w.workspaceId !== workspaceId && w.title === trimmed)) {
+            return err(request, {
+              code: 'workspace-name-conflict',
+              message: `workspace name '${trimmed}' is already in use`,
+              details: { name: trimmed },
+            })
+          }
+          workspace.title = trimmed
+          workspace.updatedAt = new Date().toISOString()
+          emitHost({ type: 'host/workspace-changed', workspace: { ...workspace } })
+        }
+        return ok(request, { workspace: { ...workspace } })
+      },
+      delete: (request) => {
+        const { workspaceId } = request.payload
+        const index = workspaces.findIndex(workspace => workspace.workspaceId === workspaceId)
+        if (index === -1) {
+          return err(request, {
+            code: 'workspace-not-found',
+            message: `no workspace ${workspaceId}`,
+            details: { workspaceId },
+          })
+        }
+        workspaces.splice(index, 1)
+        emitHost({ type: 'host/workspace-removed', workspaceId })
+        return ok(request, { deleted: true as const })
+      },
+      insertSessionBefore: (request) => {
+        const { workspaceId, sessionId, beforeSessionId } = request.payload
+        const workspace = workspaces.find(w => w.workspaceId === workspaceId)
+        if (workspace === undefined) {
+          return err(request, {
+            code: 'workspace-not-found',
+            message: `no workspace ${workspaceId}`,
+            details: { workspaceId },
+          })
+        }
+        if (!workspace.sessionIds.includes(sessionId)
+          || (beforeSessionId !== undefined && !workspace.sessionIds.includes(beforeSessionId))) {
+          return err(request, {
+            code: 'workspace-move-invalid',
+            message: `session or anchor is not accounted by workspace ${workspaceId}`,
+            details: { workspaceId, sessionId, ...beforeSessionId === undefined ? {} : { beforeSessionId } },
+          })
+        }
+        const without = workspace.sessionIds.filter(id => id !== sessionId)
+        const at = beforeSessionId === undefined ? without.length : without.indexOf(beforeSessionId)
+        const sessionIds = [...without.slice(0, at), sessionId, ...without.slice(at)]
+        if (!sessionIds.every((id, index) => id === workspace.sessionIds[index])) {
+          workspace.sessionIds = sessionIds
+          workspace.updatedAt = new Date().toISOString()
+          emitHost({ type: 'host/workspace-changed', workspace: { ...workspace } })
+        }
+        return ok(request, { workspace: { ...workspace } })
+      },
+    },
+    commands: {
+      // The catalog mirrors one session's effective view (every fixture
+      // session has an agent, like the real host).
+      list: (request) => {
+        const missing = requireSession(request)
+        if (missing !== undefined) return missing
+        return ok(request, {
+          commands: [
+            { name: 'compact', description: 'fixture：压缩当前会话上下文' },
+            { name: 'echo', description: 'fixture：回显参数', input: { hint: 'text to echo' } },
+            { name: 'goal-fixture', description: 'fixture：目标样本命令', input: { hint: '<objective>' } },
+          ],
+        })
+      },
+      // Pure admission, mirroring the host: an admitted command logs the
+      // command/run + command/done lifecycle pair (mux-broadcast by append),
+      // and the response only reports resolution.
+      execute: (request) => {
+        const missing = requireSession(request)
+        if (missing !== undefined) return missing
+        const id = request.payload.sessionId
+        // Structured split mirroring the host parser: name + verbatim rawInput
+        // (separator whitespace included) — the run payload carries no line.
+        const match = /^\/(\S+)((?:\s.*)?)$/.exec(request.payload.line.trim())
+        const name = match?.[1]
+        const args = match?.[2] ?? ''
+        const outcomes: Record<string, string> = {
+          compact: 'fixture：已压缩（假动作）',
+          echo: args.trim(),
+          'goal-fixture': `fixture：goal 已设置（${id}）`,
+        }
+        const text = name === undefined ? undefined : outcomes[name]
+        if (name === undefined || text === undefined) return ok(request, { matched: false as const })
+        const commandId = `fx-cmd-${logOf(id).length}` as CommandId
+        append(id, { type: 'command/run', data: { commandId, name, args, source: { kind: 'user' } } })
+        append(id, { type: 'command/done', data: { commandId, kind: 'success', ...text === '' ? {} : { text } } })
+        return ok(request, { matched: true as const, commandId })
+      },
+    },
+    skills: {
+      list: (request) => {
+        const missing = requireSession(request)
+        if (missing !== undefined) return missing
+        return ok(request, {
+          skills: [
+            { name: 'fixture-demo', description: 'fixture 技能样本', whenToUse: '仅供 UI 目录渲染验收' },
+          ],
+        })
+      },
     },
     goals: {
-      get: request => ok(request, { goal: request.payload.sessionId === sid('fx-alpha') ? fixtureGoal : null }),
       create: request => err(request, { code: 'internal', message: 'fixture: goals not implemented', details: {} }),
       edit: request => err(request, { code: 'internal', message: 'fixture: goals not implemented', details: {} }),
       pause: request => err(request, { code: 'internal', message: 'fixture: goals not implemented', details: {} }),
@@ -443,10 +988,16 @@ export function createFixtureApi(): ApiProxy {
         muxConns.add(conn)
         const breakNow = (): void => { conn.breakNow() }
         streamBreakers.add(breakNow)
-        // Open baseline: subscribed for attached (running) sessions + pending approval replay (stable rpcId).
+        // Open baseline: subscribed sessions + pending interactions replayed with stable rpcIds.
         for (const s of sessions) {
           if (!s.running) continue
-          conn.push({ rpcId: mint(), payload: { type: 'session/subscribed', sessionId: s.sessionId, lastSeq: (logs.get(s.sessionId)?.length ?? 0) - 1 } })
+          const log = logs.get(s.sessionId) ?? []
+          conn.push({ rpcId: mint(), payload: { type: 'session/subscribed', sessionId: s.sessionId, lastSeq: log.length - 1 } })
+          // Post-subscribe projection baseline (host parallel: recomputed unit values ride push frames).
+          const values = projectionValuesOf(log)
+          for (const key of Object.keys(values)) {
+            conn.push({ rpcId: mint(), payload: { type: 'session/projection', sessionId: s.sessionId, key, value: values[key], seq: log.length - 1 } })
+          }
         }
         conn.push({
           rpcId: pendingApprovalRpcId,
@@ -456,6 +1007,14 @@ export function createFixtureApi(): ApiProxy {
             toolName: 'dangerous_tool', reason: 'fixture 常驻占位审批（可见不可答）',
           },
         })
+        if (questionPending) {
+          conn.push({
+            rpcId: pendingQuestionRpcId,
+            payload: {
+              type: 'question/requested', sessionId: sid('fx-alpha'), questions: fixtureQuestions,
+            },
+          })
+        }
         try {
           yield* conn.drain(signal)
         } finally {
@@ -485,9 +1044,16 @@ export function createFixtureApi(): ApiProxy {
       },
     },
     respond(message: ClientResponse): Promise<RpcReceipt> {
-      // The v1 UI never answers (PendingCard is visible but not answerable); implemented for type completeness, always not-pending.
-      void message
-      return Promise.resolve({ accepted: false, reason: 'not-pending' })
+      if (!questionPending || message.rpcId !== pendingQuestionRpcId) {
+        return Promise.resolve({ accepted: false, reason: 'not-pending' })
+      }
+      questionPending = false
+      emitMux({
+        type: 'question/resolved', sessionId: sid('fx-alpha'),
+        questionRpcId: pendingQuestionRpcId,
+        outcome: message.result.ok ? 'answered' : 'cancelled',
+      })
+      return Promise.resolve({ accepted: true })
     },
   }
 }
@@ -500,7 +1066,12 @@ export function createFixtureApi(): ApiProxy {
  * to the isomorphic pipeline (InProcessApiClient over toFetchHandler(fixtureImpl)).
  */
 export class FixtureApiClient extends AbstractApiClient {
-  private readonly api = createFixtureApi()
+  private readonly api: ApiProxy
+
+  constructor() {
+    super()
+    this.api = createFixtureApi(fixtureOptionsFromLocation())
+  }
 
   protected doFetch(): Promise<Response> {
     throw new Error('FixtureApiClient overrides all protocol paths; doFetch must be unreachable')
@@ -525,10 +1096,22 @@ export class FixtureApiClient extends AbstractApiClient {
       case 'session.list': return this.api.sessions.list(request)
       case 'session.create': return this.api.sessions.create(request)
       case 'session.history': return this.api.sessions.history(request)
+      case 'session.models': return this.api.sessions.models(request)
+      case 'session.selectModel': return this.api.sessions.selectModel(request)
       case 'session.prompt': return this.api.sessions.prompt(request)
       case 'session.cancel': return this.api.sessions.cancel(request)
       case 'host.describe': return this.api.host.describe(request)
-      case 'goal.get': return this.api.goals.get(request)
+      case 'host.pickDirectory': return this.api.host.pickDirectory(request, new AbortController().signal)
+      case 'host.openPath': return this.api.host.openPath(request, new AbortController().signal)
+      case 'workspace.list': return this.api.workspace.list(request)
+      case 'workspace.create': return this.api.workspace.create(request)
+      case 'workspace.rename': return this.api.workspace.rename(request)
+      case 'workspace.delete': return this.api.workspace.delete(request)
+      case 'workspace.insertSessionBefore': return this.api.workspace.insertSessionBefore(request)
+      case 'command.list': return this.api.commands.list(request)
+      // The in-memory execute never blocks, so a never-aborting signal is faithful here.
+      case 'command.execute': return this.api.commands.execute(request, new AbortController().signal)
+      case 'skill.list': return this.api.skills.list(request)
       case 'goal.create': return this.api.goals.create(request)
       case 'goal.edit': return this.api.goals.edit(request)
       case 'goal.pause': return this.api.goals.pause(request)
@@ -579,3 +1162,16 @@ export class FixtureApiClient extends AbstractApiClient {
     return this.api.respond(message)
   }
 }
+
+/** Browser query mapping; direct unit callers pass FixtureOptions explicitly. */
+function fixtureOptionsFromLocation(): FixtureOptions {
+  if (typeof location === 'undefined') return {}
+  const query = new URLSearchParams(location.search)
+  return {
+    empty: query.get('fixture') === 'empty',
+    rejectPrompt: query.get('fixturePrompt') === 'reject',
+    failWorkspaceAttach: query.get('fixtureAttach') === 'fail',
+    dropSessionCreateResponse: query.get('fixtureSessionCreate') === 'drop-response',
+    createFrameOrder: query.get('fixtureFrames') === 'workspace-first' ? 'workspace-first' : 'session-first',
+  }
+}

packages/client/connection/src/client/index.ts

@@ -1,10 +1,7 @@
 /**
- * Browser half of the wire consumer layer (contract: api-contracts v3
- * section 3; export inventory = v3 §3.2). The wire is this package's client
- * half in its entirety — apply mounts ctx.connection: the shared api client
- * plus the connection controller handle. Mode selection (?fixture) happens
- * here so the rest of the client tree is mode-blind; the controller's sinks
- * are wired by the runtime plugin (object layer), which injects this service.
+ * Browser wire client. The plugin selects fixture or HTTP transport, provides
+ * the shared API client, and lets the runtime object layer start the stream
+ * controller with its sinks.
  */
 import type { Context } from 'cordis'
 import type { IApiClient } from './api.ts'
@@ -16,22 +13,21 @@ import { WebApiClient } from './web-api-client.ts'
 export type {
   ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
   ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
-  ToolCallView, ToolResultView,
+  ToolCallView, ToolResultView, WorkspaceApi, WorkspaceId, WorkspaceView,
+  CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
+  ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
+  ModelReasoningEffort, ModelTarget, SessionModels,
   RpcRequest, RpcResponse, RpcResult, RpcError, RpcErrorCode,
   ClientRequest, ServerResponse, ServerRequest, ClientResponse, RpcMessage, RpcReceipt,
   IApiClient, SessionId, SessionEvent, ContentBlock, StreamChunk,
-  GoalsApi, GoalView, GoalRef, GoalPhase, GoalBlockReason,
+  GoalsApi, GoalRef,
 } from './api.ts'
-export { RpcId, AbstractApiClient, resultOf, transportError } from './api.ts'
+export { RpcId, AbstractApiClient, transportError } from './api.ts'
 
-// ---- Connection loop ----
-export { ConnectionController } from './connection.ts'
+// Connection loop types are public through ConnectionHandle.start; the
+// controller remains package-internal.
 export type { ConnectionConfig, ConnectionSinks, ConnectionState }
 
-// ---- Platform client subclasses ----
-export { WebApiClient } from './web-api-client.ts'
-export { FixtureApiClient, createFixtureApi } from './fixture.ts'
-
 
 /** Required services (none — this is the wire root). */
 export const inject: string[] = []

packages/client/connection/src/http-bridge.ts

@@ -0,0 +1,59 @@
+/**
+ * node:http ↔ WHATWG fetch bridge for the /api transport (host side of the
+ * web carrier; the fetch-shaped handler itself is transport-agnostic).
+ */
+
+import type { IncomingMessage, ServerResponse } from 'node:http'
+
+/**
+ * Bridge one node:http request to the fetch-shaped handler (client close
+ * aborts; SSE bodies stream out chunk by chunk).
+ * @param req - incoming node:http request (fully read before dispatch).
+ * @param res - node:http response the bridge writes and owns to completion.
+ * @param apiHandler - fetch-shaped API carrier the request is dispatched to.
+ */
+export async function bridge(req: IncomingMessage, res: ServerResponse, apiHandler: { fetch: typeof fetch }): Promise<void> {
+  const abort = new AbortController()
+  // Client-disconnect detection MUST hang off the response, not the request:
+  // since Node 16, IncomingMessage 'close' fires as soon as the request body is
+  // fully consumed (immediately for a bodyless GET), which would abort every SSE
+  // stream right after open. ServerResponse 'close' fires on connection teardown;
+  // writableEnded distinguishes a normal end() from the client going away.
+  res.on('close', () => {
+    if (!res.writableEnded) abort.abort()
+  })
+  const chunks: Buffer[] = []
+  for await (const chunk of req) chunks.push(chunk as Buffer)
+  /* v8 ignore next 3 -- `??` arms: node:http always sets url/method on server
+  requests; the fields are only optional on the client-side IncomingMessage type */
+  const request = new Request(new URL(req.url ?? '/', 'http://dsh.internal'), {
+    method: req.method ?? 'GET',
+    headers: Object.fromEntries(Object.entries(req.headers).filter(([, v]) => typeof v === 'string') as [string, string][]),
+    ...chunks.length > 0 ? { body: Buffer.concat(chunks) } : {},
+    signal: abort.signal,
+  })
+  const response = await apiHandler.fetch(request)
+  res.writeHead(response.status, Object.fromEntries(response.headers.entries()))
+  if (response.body === null) {
+    res.end()
+    return
+  }
+  for await (const chunk of response.body) {
+    // Backpressure: a false return means the socket buffer is full — wait for drain
+    // instead of buffering unboundedly (slow/suspended SSE consumers). 'close' also
+    // resolves so a mid-wait disconnect can't park this loop forever; the close
+    // handler above aborts the handler stream, which then ends the iteration.
+    if (!res.write(chunk)) {
+      await new Promise<void>((resolve) => {
+        const done = (): void => {
+          res.off('drain', done)
+          res.off('close', done)
+          resolve()
+        }
+        res.once('drain', done)
+        res.once('close', done)
+      })
+    }
+  }
+  res.end()
+}

packages/client/connection/src/index.ts

@@ -1,10 +1,40 @@
-/**
- * Connection plugin, node half. The package IS a dshClient plugin: the wire
- * consumer layer lives in its client half in full (src/client/ — contract:
- * api-contracts v3 section 3, inventory §3.2); consumers import the /client
- * subpath. The empty apply exists so the plugin appears in the host Loader
- * (lifecycle governance + dshClient discovery).
- */
+/** Host HTTP bridge for browser-client RPC. */
+import type { Context } from 'cordis'
+// Activates the httpServer Context merge used below.
+import type { WebRoute } from '@deepseek-ai/dsh-host-webserver'
+import { toFetchHandler } from '@deepseek-ai/dsh-host-apiproxy'
+import { API_PATH } from './api-path.ts'
+import { bridge } from './http-bridge.ts'
+import { isTrustedNativeDialogRequest } from './native-dialog-request.ts'
 
-/** Host plugin body — no host-side behavior for the connection plugin. */
-export function apply(_ctx: unknown): void {}
+export { API_PATH } from './api-path.ts'
+
+/** Stable Cordis plugin name. */
+export const name = 'client-connection'
+
+/** Services required before mounting the route. */
+export const inject = ['httpServer', 'apiProxy']
+
+/**
+ * Mounts the API gateway under the browser transport prefix.
+ * @param ctx - Host plugin context.
+ */
+export function apply(ctx: Context): void {
+  const apiHandler = toFetchHandler(ctx.apiProxy)
+  const route: WebRoute = {
+    kind: 'prefix',
+    path: API_PATH,
+    handler: async (req, res) => {
+      const pathname = new URL(req.url ?? '/', 'http://dsh.internal').pathname
+      if ((pathname === `${API_PATH}/host.pickDirectory`
+        || pathname === `${API_PATH}/host.openPath`)
+        && !isTrustedNativeDialogRequest(req)) {
+        res.writeHead(403)
+        res.end('forbidden')
+        return
+      }
+      await bridge(req, res, apiHandler)
+    },
+  }
+  ctx.effect(() => ctx.httpServer.register(route), 'client-connection: /api route')
+}

packages/client/connection/src/invariant.ts

@@ -15,10 +15,11 @@ export const name = 'client-connection-invariant'
 export const inject = ['invariants']
 
 /**
- * No runtime invariant: the pure wire layer emits no cordis events and owns no
+ * No runtime invariant: the wire layer emits no cordis events and owns no
  * mutable cross-plugin relation — stream/reconnect sequencing is exercised
- * directly by its behavior specs, and rpcId round-trip discipline is owned by
- * the apiproxy contract layer.
+ * directly by its behavior specs, rpcId round-trip discipline is owned by the
+ * apiproxy contract layer, and the node half's single route registration's
+ * register/dispose symmetry is audited by the webserver package's invariant.
  */
 const install: InvariantInstaller = () => {}
 

packages/client/connection/src/native-dialog-request.ts

@@ -0,0 +1,52 @@
+/** Trust check for browser requests that can invoke privileged native host actions. */
+
+import type { IncomingHttpHeaders } from 'node:http'
+
+interface NativeDialogRequest {
+  headers: IncomingHttpHeaders
+  socket: { remoteAddress?: string | undefined }
+}
+
+function header(headers: IncomingHttpHeaders, name: string): string | undefined {
+  const value = headers[name]
+  return typeof value === 'string' ? value : undefined
+}
+
+function isLoopback(address: string | undefined): boolean {
+  if (address === undefined) return false
+  if (address === '::1') return true
+  const ipv4 = address.startsWith('::ffff:') ? address.slice('::ffff:'.length) : address
+  const first = ipv4.split('.')[0]
+  return first === '127'
+}
+
+function isLoopbackHostname(hostname: string): boolean {
+  if (hostname === 'localhost' || hostname === '[::1]' || hostname === '::1') return true
+  const parts = hostname.split('.')
+  return parts.length === 4
+    && parts[0] === '127'
+    && parts.every(part => /^\d{1,3}$/.test(part) && Number(part) <= 255)
+}
+
+/**
+ * Require a local socket plus browser-controlled same-origin metadata.
+ * @param request - the node HTTP request facts used by the carrier guard.
+ * @returns true only for a same-origin browser request whose peer and URL are loopback.
+ */
+export function isTrustedNativeDialogRequest(request: NativeDialogRequest): boolean {
+  if (!isLoopback(request.socket.remoteAddress)) return false
+  if (header(request.headers, 'sec-fetch-site') !== 'same-origin') return false
+  const origin = header(request.headers, 'origin')
+  const host = header(request.headers, 'host')
+  if (origin === undefined || host === undefined) return false
+  try {
+    const parsed = new URL(origin)
+    const hostUrl = new URL(`http://${host}`)
+    return (parsed.protocol === 'http:' || parsed.protocol === 'https:')
+      && parsed.host === host
+      && isLoopbackHostname(parsed.hostname)
+      && isLoopbackHostname(hostUrl.hostname)
+  } catch {
+    return false
+  }
+}

packages/client/connection/tests/fake-api.ts

@@ -1,8 +1,10 @@
 // Test-local programmable IApiClient fake (NOT the fixture: fixture is a demo
 // data source on a real clock; behavior tests need per-case responses and
 // deferred-controlled timing). Streams are hand pumps: pushMux/pushHost.
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type {
-  HostFrame, IApiClient, MuxFrame, RpcRequest, RpcResponse, SessionId,
+  CommandDescriptor, HostFrame, IApiClient, ModelTarget, MuxFrame,
+  RpcRequest, RpcResponse, SessionId, SessionModels, SkillEntry,
 } from '../src/client/api.ts'
 import { RpcId } from '../src/client/api.ts'
 
@@ -44,13 +46,29 @@ export class FakeApiClient implements IApiClient {
   onList: (payload: unknown) => Promise<RpcResponse<{ items: never[] }>> = () => Promise.resolve(ok({ items: [] }))
   onCreate: (payload: unknown) => Promise<RpcResponse<{ sessionId: SessionId }>> = () => Promise.resolve(ok({ sessionId: 'fk-new' as SessionId }))
   onHistory: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number })
-  => Promise<RpcResponse<{ events: never[]; hasMore: boolean }>> =
-    () => Promise.resolve(ok({ events: [], hasMore: false }))
+  => Promise<RpcResponse<{ events: never[]; hasMore: boolean; modelTarget: ModelTarget }>> =
+    () => Promise.resolve(ok({
+      events: [],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'deepseek-chat' },
+    }))
 
+  onModels: (payload: unknown) => Promise<RpcResponse<SessionModels>> = () => Promise.resolve(ok({
+    current: { provider: 'deepseek', model: 'deepseek-chat' },
+    groups: [],
+    failures: [],
+  }))
+  onSelectModel: (payload: ModelTarget & { sessionId: SessionId })
+  => Promise<RpcResponse<{ selected: ModelTarget }>> =
+    payload => Promise.resolve(ok({ selected: { provider: payload.provider, model: payload.model } }))
   onPrompt: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
   onCancel: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
   onDescribe: (payload: unknown) => Promise<RpcResponse<{ version: string; cwd: string; attachedSessions: number }>> =
     () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0 }))
+  onPickDirectory: (payload: unknown) => Promise<RpcResponse<{ path: string | null }>> =
+    () => Promise.resolve(ok({ path: null }))
+  onOpenPath: (payload: unknown) => Promise<RpcResponse<{ opened: true }>> =
+    () => Promise.resolve(ok({ opened: true as const }))
 
   private readonly muxConns: StreamConn<MuxFrame>[] = []
   private readonly hostConns: StreamConn<HostFrame>[] = []
@@ -63,16 +81,53 @@ export class FakeApiClient implements IApiClient {
     create: (payload: unknown) => this.record('session.create', payload, this.onCreate(payload)),
     history: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number }) =>
       this.record('session.history', payload, this.onHistory(payload)),
+    models: (payload: unknown) => this.record('session.models', payload, this.onModels(payload)),
+    selectModel: (payload: ModelTarget & { sessionId: SessionId }) =>
+      this.record('session.selectModel', payload, this.onSelectModel(payload)),
     prompt: (payload: unknown) => this.record('session.prompt', payload, this.onPrompt(payload)),
     cancel: (payload: unknown) => this.record('session.cancel', payload, this.onCancel(payload)),
   }
 
   readonly host: IApiClient['host'] = {
     describe: payload => this.record('host.describe', payload, this.onDescribe(payload)),
+    pickDirectory: payload => this.record('host.pickDirectory', payload, this.onPickDirectory(payload)),
+    openPath: payload => this.record('host.openPath', payload, this.onOpenPath(payload)),
+  }
+
+  readonly workspace: IApiClient['workspace'] = {
+    list: (payload: unknown) => this.record('workspace.list', payload, Promise.resolve(ok({ items: [] }))),
+    create: (payload: unknown) => this.record('workspace.create', payload, Promise.resolve(ok({
+      workspace: { workspaceId: 'fk-ws' as never, path: '/f/ws', title: 'ws', sessionIds: [], createdAt: '0', updatedAt: '0' },
+      created: true,
+    }))),
+    rename: (payload: unknown) => this.record('workspace.rename', payload, Promise.resolve(ok({
+      workspace: { workspaceId: 'fk-ws' as never, path: '/f/ws', title: 'ws', sessionIds: [], createdAt: '0', updatedAt: '0' },
+    }))),
+    delete: (payload: unknown) => this.record('workspace.delete', payload, Promise.resolve(ok({ deleted: true as const }))),
+    insertSessionBefore: (payload: unknown) => this.record('workspace.insertSessionBefore', payload, Promise.resolve(ok({
+      workspace: { workspaceId: 'fk-ws' as never, path: '/f/ws', title: 'ws', sessionIds: [], createdAt: '0', updatedAt: '0' },
+    }))),
+  }
+
+  // Payloads stay `unknown` (lint-lane note above); response rows are the real
+  // wire shapes so cases can program catalogs and skill lists without casts.
+  onCommandList: (payload: unknown) => Promise<RpcResponse<{ commands: CommandDescriptor[] }>>
+    = () => Promise.resolve(ok({ commands: [] }))
+  onCommandExecute: (payload: unknown) => Promise<RpcResponse<{ matched: boolean; commandId?: CommandId }>>
+    = () => Promise.resolve(ok({ matched: false }))
+  onSkillList: (payload: unknown) => Promise<RpcResponse<{ skills: SkillEntry[] }>>
+    = () => Promise.resolve(ok({ skills: [] }))
+
+  readonly commands: IApiClient['commands'] = {
+    list: (payload: unknown) => this.record('command.list', payload, this.onCommandList(payload)),
+    execute: (payload: unknown) => this.record('command.execute', payload, this.onCommandExecute(payload)),
+  }
+
+  readonly skills: IApiClient['skills'] = {
+    list: (payload: unknown) => this.record('skill.list', payload, this.onSkillList(payload)),
   }
 
   readonly goals: IApiClient['goals'] = {
-    get: payload => this.record('goal.get', payload, Promise.resolve(ok({ goal: null }))),
     create: payload => this.record('goal.create', payload, Promise.resolve(ok({ goal: null as unknown as never }))),
     edit: payload => this.record('goal.edit', payload, Promise.resolve(ok({ goal: null as unknown as never }))),
     pause: payload => this.record('goal.pause', payload, Promise.resolve(ok({ goal: null as unknown as never }))),

packages/client/connection/tests/fixture-commands.spec.ts

@@ -0,0 +1,109 @@
+/**
+ * Fixture commands/skills domains: contract-shape conformance for the two
+ * domains added to ApiProxy — rpcId echo, session-addressed catalogs, execute
+ * parse/dispatch, skill.list session resolution, and the FixtureApiClient
+ * dispatch rows.
+ */
+import { describe, expect, it } from 'vitest'
+import type { SessionId } from '../src/client/api.ts'
+import { RpcId } from '../src/client/api.ts'
+import type { RpcRequest } from '../src/client/api.ts'
+import { FixtureApiClient, createFixtureApi } from '../src/client/fixture.ts'
+
+const sid = (id: string): SessionId => id as SessionId
+let reqCount = 0
+const req = <P>(payload: P): RpcRequest<P> => ({ rpcId: RpcId(`t-${reqCount++}`), payload })
+const signal = new AbortController().signal
+
+describe('createFixtureApi commands/skills', () => {
+  it('serves the addressed session catalog with rpcId echo', async () => {
+    const api = createFixtureApi()
+    const request = req({ sessionId: sid('fx-alpha') })
+    const response = await api.commands.list(request)
+    expect(response.rpcId).toBe(request.rpcId)
+    if (!response.result.ok) throw new Error('list failed')
+    const commands = response.result.value.commands
+    expect(commands.map(c => c.name)).toEqual(['compact', 'echo', 'goal-fixture'])
+    // input hint rides only the commands declaring it.
+    const echo = commands.find(c => c.name === 'echo')
+    expect(echo?.input?.hint).toBeTruthy()
+    expect(commands.find(c => c.name === 'compact')?.input).toBeUndefined()
+  })
+
+  it('rejects a catalog request for an unknown session', async () => {
+    const api = createFixtureApi()
+    const response = await api.commands.list(req({ sessionId: sid('fx-nope') }))
+    expect(response.result).toMatchObject({ ok: false, error: { code: 'session-not-found' } })
+  })
+
+  it('executes a known command line: pure admission plus a mux-broadcast lifecycle pair', async () => {
+    const api = createFixtureApi()
+    const frames: unknown[] = []
+    const abort = new AbortController()
+    const stream = api.events.mux(req({}), abort.signal)
+    const pump = (async () => {
+      for await (const frame of stream) {
+        frames.push(frame.payload)
+        if (frames.filter(f => (f as { type: string }).type === 'session/event').length >= 2) abort.abort()
+      }
+    })()
+    const response = await api.commands.execute(req({ sessionId: sid('fx-alpha'), line: '/echo hello world' }), signal)
+    if (!response.result.ok) throw new Error('execute failed')
+    expect(response.result.value).toMatchObject({ matched: true })
+    expect(response.result.value.commandId).toBeTruthy()
+    await pump
+    const events = frames
+      .filter((f): f is { type: string; event: { type: string; data: Record<string, unknown> } } => (f as { type: string }).type === 'session/event')
+      .map(f => f.event)
+    expect(events).toMatchObject([
+      { type: 'command/run', data: { name: 'echo', args: ' hello world', source: { kind: 'user' } } },
+      { type: 'command/done', data: { kind: 'success', text: 'hello world' } },
+    ])
+    expect(events[0]?.data.commandId).toBe(events[1]?.data.commandId)
+  })
+
+  it('addresses execute to the session; an unknown session errs', async () => {
+    const api = createFixtureApi()
+    const hit = await api.commands.execute(req({ sessionId: sid('fx-alpha'), line: '/goal-fixture ship' }), signal)
+    if (!hit.result.ok) throw new Error('execute failed')
+    expect(hit.result.value.matched).toBe(true)
+
+    const missing = await api.commands.execute(req({ sessionId: sid('fx-nope'), line: '/goal-fixture ship' }), signal)
+    expect(missing.result).toMatchObject({ ok: false, error: { code: 'session-not-found' } })
+  })
+
+  it('falls to matched:false on unknown names and non-command lines', async () => {
+    const api = createFixtureApi()
+    for (const line of ['/nope', 'plain text', '/']) {
+      const response = await api.commands.execute(req({ sessionId: sid('fx-alpha'), line }), signal)
+      if (!response.result.ok) throw new Error('execute failed')
+      // Pure admission value: the matched bit is the whole response shape.
+      expect(response.result.value).toEqual({ matched: false })
+    }
+  })
+
+  it('serves the skill catalog for the addressed session and rejects unknown sessions', async () => {
+    const api = createFixtureApi()
+    const response = await api.skills.list(req({ sessionId: sid('fx-alpha') }))
+    if (!response.result.ok) throw new Error('skill list failed')
+    expect(response.result.value.skills[0]?.name).toBe('fixture-demo')
+
+    const missingSession = await api.skills.list(req({ sessionId: sid('fx-nope') }))
+    expect(missingSession.result).toMatchObject({ ok: false, error: { code: 'session-not-found' } })
+  })
+})
+
+describe('FixtureApiClient command/skill dispatch', () => {
+  it('routes the three method keys through the in-memory dispatch table', async () => {
+    const client = new FixtureApiClient()
+    const list = await client.commands.list({ sessionId: sid('fx-alpha') })
+    if (!list.result.ok) throw new Error('command.list failed')
+    expect(list.result.value.commands.length).toBeGreaterThan(0)
+    const executed = await client.commands.execute({ sessionId: sid('fx-alpha'), line: '/compact' })
+    if (!executed.result.ok) throw new Error('command.execute failed')
+    expect(executed.result.value.matched).toBe(true)
+    const skills = await client.skills.list({ sessionId: sid('fx-alpha') })
+    if (!skills.result.ok) throw new Error('skill.list failed')
+    expect(skills.result.value.skills.length).toBeGreaterThan(0)
+  })
+})

packages/client/connection/tests/fixture.spec.ts

@@ -5,7 +5,7 @@
  * the hand-written fixture/host parallel implementations.
  */
 import { afterEach, describe, expect, it, vi } from 'vitest'
-import type { SessionId } from '../src/client/api.ts'
+import type { SessionId, WorkspaceId } from '../src/client/api.ts'
 import { RpcId } from '../src/client/api.ts'
 import type { HostFrame, MuxFrame, RpcMessage, RpcRequest } from '../src/client/api.ts'
 import { FixtureApiClient, createFixtureApi } from '../src/client/fixture.ts'
@@ -18,6 +18,7 @@ interface TimingHooks {
   setHistoryDelay(ms: number): void
   failNextHistory(): void
   appendUser(id: string, msg: string): void
+  appendTitle(id: string, title: string): void
   appendSilent(id: string, msg: string): void
   breakStreams(): void
 }
@@ -64,10 +65,60 @@ describe('createFixtureApi', () => {
     const clamped = await api.sessions.history(req({ sessionId: sid('fx-alpha'), beforeSeq: -5, maxMessages: 10 }))
     if (!clamped.result.ok) throw new Error('clamped failed')
     expect(clamped.result.value.events).toEqual([])
-    // Unknown session: empty page, not an error (history of a bare id).
+    // Unknown session: empty page, not an error (history of a bare id). The
+    // tail block still rides it — empty-log cut at -1, the host convention.
     const empty = await api.sessions.history(req({ sessionId: sid('no-such'), maxMessages: 10 }))
     if (!empty.result.ok) throw new Error('empty failed')
-    expect(empty.result.value).toEqual({ events: [], hasMore: false })
+    // Fixture composes the todos unit (host parallel when tool-todo is mounted): null before any write.
+    expect(empty.result.value).toEqual({
+      events: [], hasMore: false, projections: { asOfSeq: -1, values: { todos: null } },
+    })
+  })
+
+  it('serves grouped models and keeps a selected target for later history and fixture requests', async () => {
+    const api = createFixtureApi()
+    const sessionId = sid('fx-alpha')
+    const catalog = await api.sessions.models(req({ sessionId }))
+    if (!catalog.result.ok) throw new Error('models failed')
+    expect(catalog.result.value.groups.map(group => group.name)).toEqual(['DeepSeek', 'OpenAI'])
+    expect(catalog.result.value.groups[0]?.models.map(model => model.id))
+      .toEqual(['deepseek-v4-flash', 'deepseek-v4-pro'])
+
+    const selected = await api.sessions.selectModel(req({
+      sessionId,
+      provider: 'openai',
+      model: 'gpt-5',
+    }))
+    if (!selected.result.ok) throw new Error('selection failed')
+    expect(selected.result.value.selected).toEqual({ provider: 'openai', model: 'gpt-5' })
+    const history = await api.sessions.history(req({ sessionId }))
+    if (!history.result.ok) throw new Error('history failed')
+
+    const prompt = await api.sessions.prompt(req({
+      sessionId,
+      mode: 'queue',
+      content: [{ type: 'text', text: 'report model' }],
+    }))
+    expect(prompt.result.ok).toBe(true)
+    await new Promise(resolve => setTimeout(resolve, 600))
+    const after = await api.sessions.history(req({ sessionId }))
+    if (!after.result.ok) throw new Error('history failed')
+    expect(JSON.stringify(after.result.value.events)).toContain('openai/gpt-5')
+  })
+
+  it('emits the todo/write snapshot at the real tool boundary: between tool/call and tool/result, timestamps monotonic', async () => {
+    const api = createFixtureApi()
+    const tail = await api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 10 }))
+    if (!tail.result.ok) throw new Error('history failed')
+    const events = tail.result.value.events.map(e => e.event)
+    const todoAt = events.findIndex(e => e.type === 'todo/write')
+    expect(todoAt).toBeGreaterThan(0)
+    // Production ordering (the tool appends mid-execution): call → snapshot → result.
+    expect(events[todoAt - 1]?.type).toBe('tool/call')
+    expect(events[todoAt + 1]?.type).toBe('tool/result')
+    const times = events.slice(todoAt - 1, todoAt + 2).map(e => e.time)
+    expect(times[0]).toBeLessThanOrEqual(times[1] ?? 0)
+    expect(times[1]).toBeLessThanOrEqual(times[2] ?? 0)
   })
 
   it('create adds a session and pushes host/session-added to open host streams', async () => {
@@ -86,7 +137,7 @@ describe('createFixtureApi', () => {
     await consuming
     if (!created.result.ok) throw new Error('create failed')
     const createdId = created.result.value.sessionId
-    expect(seen).toEqual([{ type: 'host/session-added', sessionId: createdId }])
+    expect(seen).toEqual([{ type: 'host/session-added', sessionId: createdId, blank: true, cwd: '/tmp/fixture' }])
     const list = await api.sessions.list(req({}))
     if (!list.result.ok) throw new Error('list failed')
     expect(list.result.value.items.some(s => s.sessionId === createdId)).toBe(true)
@@ -113,7 +164,7 @@ describe('createFixtureApi', () => {
     const missing = await api.sessions.prompt(req({ sessionId: sid('ghost'), mode: 'queue' as const, content: [{ type: 'text' as const, text: 'x' }] }))
     expect(missing.result).toMatchObject({ ok: false, error: { code: 'session-not-found', details: { sessionId: 'ghost' } } })
     // Real prompt: replay starts (running flips true), cancel freezes it.
-    const accepted = await api.sessions.prompt(req({ sessionId: id, mode: 'queue' as const, content: [{ type: 'text' as const, text: '取消我' }] }))
+    const accepted = await api.sessions.prompt(req({ sessionId: id, mode: 'queue' as const, content: [{ type: 'text' as const, text: 'render markdown' }] }))
     expect(accepted.result).toMatchObject({ ok: true, value: { accepted: true } })
     await new Promise(resolve => setTimeout(resolve, 120)) // a couple of typewriter ticks
     await api.sessions.cancel(req({ sessionId: id }))
@@ -148,14 +199,14 @@ describe('createFixtureApi', () => {
     expect(types.at(-1)).toBe('turn/end') // steer did not restart the turn
   })
 
-  it('mux open replays the baseline: subscribed for running sessions + the resident approval with a stable rpcId', async () => {
+  it('mux open replays subscribed sessions and resident interactions with stable rpcIds', async () => {
     const api = createFixtureApi()
     const openOnce = async (): Promise<RpcRequest<MuxFrame>[]> => {
       const abort = new AbortController()
       const envelopes: RpcRequest<MuxFrame>[] = []
       for await (const envelope of api.events.mux(req({}), abort.signal)) {
         envelopes.push(envelope)
-        if (envelopes.length >= 2) abort.abort()
+        if (envelopes.length >= 4) abort.abort()
       }
       return envelopes
     }
@@ -163,8 +214,13 @@ describe('createFixtureApi', () => {
     const second = await openOnce()
     expect(first[0]?.payload).toMatchObject({ type: 'session/subscribed', sessionId: 'fx-alpha' })
     expect((first[0]?.payload as { lastSeq: number }).lastSeq).toBeGreaterThan(0)
-    expect(first[1]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
-    expect(second[1]?.rpcId).toBe(first[1]?.rpcId) // stable rpcId across replays (host replay semantics)
+    // Projection baseline frames follow the subscribed frame (title + todos units).
+    expect(first[1]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'title', value: 'Fixture 历史会话' })
+    expect(first[2]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'todos' })
+    expect(first[3]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
+    expect(second[3]?.rpcId).toBe(first[3]?.rpcId) // stable rpcId across replays (host replay semantics)
+    expect(first[4]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
+    expect(second[4]?.rpcId).toBe(first[4]?.rpcId)
   })
 
   it('steer with no replay in flight falls through to a fresh queued turn; non-text blocks stringify empty', async () => {
@@ -217,15 +273,330 @@ describe('createFixtureApi', () => {
     }
   })
 
-  it('respond is a typed stub: always not-pending', async () => {
+  it('respond resolves the resident question once and rejects duplicate or unrelated ids', async () => {
     const api = createFixtureApi()
     expect(await api.respond({ type: 'client-response', rpcId: RpcId('x'), result: { ok: true, value: {} } })).toEqual({ accepted: false, reason: 'not-pending' })
+    const abort = new AbortController()
+    let question: RpcRequest<MuxFrame> | undefined
+    for await (const envelope of api.events.mux(req({}), abort.signal)) {
+      if (envelope.payload.type !== 'question/requested') continue
+      question = envelope
+      abort.abort()
+    }
+    if (question === undefined) throw new Error('fixture question missing')
+    const response = { type: 'client-response' as const, rpcId: question.rpcId, result: { ok: true as const, value: {} } }
+    expect(await api.respond(response)).toEqual({ accepted: true })
+    expect(await api.respond(response)).toEqual({ accepted: false, reason: 'not-pending' })
+
+    const replayAbort = new AbortController()
+    const replayed = await collect(api.events.mux(req({}), replayAbort.signal), replayAbort, frames => frames.length === 2)
+    expect(replayed.every(frame => frame.type !== 'question/requested')).toBe(true)
+
+    const cancelledApi = createFixtureApi()
+    const cancelAbort = new AbortController()
+    let cancelQuestion: RpcRequest<MuxFrame> | undefined
+    for await (const envelope of cancelledApi.events.mux(req({}), cancelAbort.signal)) {
+      if (envelope.payload.type !== 'question/requested') continue
+      cancelQuestion = envelope
+      cancelAbort.abort()
+    }
+    if (cancelQuestion === undefined) throw new Error('fixture cancellation question missing')
+    expect(await cancelledApi.respond({
+      type: 'client-response', rpcId: cancelQuestion.rpcId,
+      result: { ok: false, error: { code: 'cancelled', message: 'skip', details: {} } },
+    })).toEqual({ accepted: true })
   })
 
   it('describe answers the fixture identity', async () => {
     const api = createFixtureApi()
     const response = await api.host.describe(req({}))
     expect(response.result).toMatchObject({ ok: true, value: { version: '0.0.0-fixture', attachedSessions: 1 } })
+    const empty = await createFixtureApi({ empty: true }).host.describe(req({}))
+    expect(empty.result).toMatchObject({ ok: true, value: { attachedSessions: 0 } })
+  })
+
+  it('workspace.list serves the resident account and create reuses on path collision', async () => {
+    const api = createFixtureApi()
+    const listed = await api.workspace.list(req({}))
+    if (!listed.result.ok) throw new Error('list failed')
+    expect(listed.result.value.items).toEqual([expect.objectContaining({
+      workspaceId: 'fx-ws-fixture', path: '/tmp/fixture', title: 'fixture',
+      sessionIds: ['fx-alpha', 'fx-beta', 'fx-gamma'],
+    })])
+    // path collision → the existing entity comes back, created:false, no frame.
+    const reused = await api.workspace.create(req({ path: '/tmp/fixture' }))
+    if (!reused.result.ok) throw new Error('reuse failed')
+    expect(reused.result.value).toMatchObject({ created: false, workspace: { workspaceId: 'fx-ws-fixture' } })
+  })
+
+  it('workspace.create by name mints a new entity and pushes host/workspace-changed', async () => {
+    const api = createFixtureApi()
+    const abort = new AbortController()
+    const seen: HostFrame[] = []
+    const consuming = (async () => {
+      for await (const envelope of api.events.host(req({}), abort.signal)) {
+        seen.push(envelope.payload)
+        abort.abort()
+      }
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10))
+    const created = await api.workspace.create(req({ name: 'nova' }))
+    if (!created.result.ok) throw new Error('create failed')
+    expect(created.result.value.created).toBe(true)
+    expect(created.result.value.workspace).toMatchObject({
+      path: '/tmp/fixture-workspaces/nova', title: 'nova', sessionIds: [],
+    })
+    await consuming
+    expect(seen).toEqual([{ type: 'host/workspace-changed', workspace: created.result.value.workspace }])
+    // path spelling falls back to the basename when no title/name rides along.
+    const pathOnly = await api.workspace.create(req({ path: '/tmp/fixture-elsewhere/base' }))
+    if (!pathOnly.result.ok) throw new Error('pathOnly failed')
+    expect(pathOnly.result.value.workspace.title).toBe('base')
+    // Degenerate spellings reach the impl unfiltered (the fixture carrier has
+    // no schema gate): both-absent falls back to the bucket dir, and a
+    // basename-less path serves as its own title.
+    const bare = await api.workspace.create(req({}))
+    if (!bare.result.ok) throw new Error('bare failed')
+    expect(bare.result.value.workspace).toMatchObject({ path: '/tmp/fixture-workspaces/', title: 'fixture-workspaces' })
+    const rootPath = await api.workspace.create(req({ path: '/' }))
+    if (!rootPath.result.ok) throw new Error('rootPath failed')
+    expect(rootPath.result.value.workspace.title).toBe('/')
+  })
+
+  it('workspace.rename covers not-found, conflict, no-op, and the changed frame', async () => {
+    const api = createFixtureApi()
+    const abort = new AbortController()
+    const seen: HostFrame[] = []
+    const consuming = (async () => {
+      for await (const envelope of api.events.host(req({}), abort.signal)) {
+        seen.push(envelope.payload)
+        if (seen.length >= 2) abort.abort()
+      }
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10))
+    const wsid = 'fx-ws-fixture' as WorkspaceId
+    const missing = await api.workspace.rename(req({ workspaceId: 'fx-ws-void' as WorkspaceId, title: 'x' }))
+    expect(missing.result).toMatchObject({ ok: false, error: { code: 'workspace-not-found', details: { workspaceId: 'fx-ws-void' } } })
+
+    await api.workspace.create(req({ name: 'occupied' }))
+    const conflict = await api.workspace.rename(req({ workspaceId: wsid, title: ' occupied ' }))
+    expect(conflict.result).toMatchObject({ ok: false, error: { code: 'workspace-name-conflict', details: { name: 'occupied' } } })
+
+    const noop = await api.workspace.rename(req({ workspaceId: wsid, title: ' fixture ' }))
+    if (!noop.result.ok) throw new Error('no-op rename failed')
+    expect(noop.result.value.workspace.title).toBe('fixture')
+
+    const renamed = await api.workspace.rename(req({ workspaceId: wsid, title: 'renamed' }))
+    if (!renamed.result.ok) throw new Error('rename failed')
+    expect(renamed.result.value.workspace.title).toBe('renamed')
+    await consuming
+    // Only the create and the effective rename emit frames; the no-op stays silent.
+    expect(seen.map(f => f.type)).toEqual(['host/workspace-changed', 'host/workspace-changed'])
+  })
+
+  it('workspace.insertSessionBefore moves, appends, no-ops, and rejects invalid ids', async () => {
+    const api = createFixtureApi()
+    const wsid = 'fx-ws-fixture' as WorkspaceId
+    const missing = await api.workspace.insertSessionBefore(req({ workspaceId: 'fx-ws-void' as WorkspaceId, sessionId: sid('fx-alpha') }))
+    expect(missing.result).toMatchObject({ ok: false, error: { code: 'workspace-not-found' } })
+    const ghost = await api.workspace.insertSessionBefore(req({ workspaceId: wsid, sessionId: sid('fx-ghost') }))
+    expect(ghost.result).toMatchObject({ ok: false, error: { code: 'workspace-move-invalid', details: { sessionId: 'fx-ghost' } } })
+    const badAnchor = await api.workspace.insertSessionBefore(req({ workspaceId: wsid, sessionId: sid('fx-alpha'), beforeSessionId: sid('fx-ghost') }))
+    expect(badAnchor.result).toMatchObject({ ok: false, error: { code: 'workspace-move-invalid', details: { beforeSessionId: 'fx-ghost' } } })
+
+    const moved = await api.workspace.insertSessionBefore(req({ workspaceId: wsid, sessionId: sid('fx-gamma'), beforeSessionId: sid('fx-beta') }))
+    if (!moved.result.ok) throw new Error('move failed')
+    expect(moved.result.value.workspace.sessionIds).toEqual(['fx-alpha', 'fx-gamma', 'fx-beta'])
+    const appended = await api.workspace.insertSessionBefore(req({ workspaceId: wsid, sessionId: sid('fx-alpha') }))
+    if (!appended.result.ok) throw new Error('append failed')
+    expect(appended.result.value.workspace.sessionIds).toEqual(['fx-gamma', 'fx-beta', 'fx-alpha'])
+    const before = appended.result.value.workspace.updatedAt
+    const noop = await api.workspace.insertSessionBefore(req({ workspaceId: wsid, sessionId: sid('fx-alpha') }))
+    if (!noop.result.ok) throw new Error('no-op move failed')
+    expect(noop.result.value.workspace.sessionIds).toEqual(['fx-gamma', 'fx-beta', 'fx-alpha'])
+    expect(noop.result.value.workspace.updatedAt).toBe(before)
+  })
+
+  it('workspace.delete removes only the Workspace row and emits the removal frame', async () => {
+    const api = createFixtureApi()
+    const abort = new AbortController()
+    const seen: HostFrame[] = []
+    const consuming = (async () => {
+      for await (const envelope of api.events.host(req({}), abort.signal)) {
+        seen.push(envelope.payload)
+        abort.abort()
+      }
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10))
+    const missing = await api.workspace.delete(req({ workspaceId: 'fx-ws-void' as WorkspaceId }))
+    expect(missing.result).toMatchObject({ ok: false, error: { code: 'workspace-not-found' } })
+    const deleted = await api.workspace.delete(req({ workspaceId: 'fx-ws-fixture' as WorkspaceId }))
+    expect(deleted.result).toEqual({ ok: true, value: { deleted: true } })
+    await consuming
+    expect(seen).toEqual([{ type: 'host/workspace-removed', workspaceId: 'fx-ws-fixture' }])
+    const list = await api.workspace.list(req({}))
+    if (!list.result.ok) throw new Error('workspace list failed')
+    expect(list.result.value.items.some(workspace => workspace.workspaceId === 'fx-ws-fixture')).toBe(false)
+    const sessions = await api.sessions.list(req({}))
+    if (!sessions.result.ok) throw new Error('session list failed')
+    expect(sessions.result.value.items.map(session => session.sessionId)).toContain('fx-alpha')
+  })
+
+  it('session.create({workspaceId}) lands on the account and unknown ids error', async () => {
+    const api = createFixtureApi()
+    const abort = new AbortController()
+    const seen: HostFrame[] = []
+    const consuming = (async () => {
+      for await (const envelope of api.events.host(req({}), abort.signal)) {
+        seen.push(envelope.payload)
+        if (seen.length >= 2) abort.abort()
+      }
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10))
+    const missing = await api.sessions.create(req({ workspaceId: 'fx-ws-void' as WorkspaceId }))
+    expect(missing.result).toMatchObject({ ok: false, error: { code: 'workspace-not-found', details: { workspaceId: 'fx-ws-void' } } })
+    const created = await api.sessions.create(req({ workspaceId: 'fx-ws-fixture' as WorkspaceId }))
+    if (!created.result.ok) throw new Error('create failed')
+    const id = created.result.value.sessionId
+    await consuming
+    // The session lands with the workspace's path as cwd, and the account
+    // write pushes the fresh workspace snapshot after session-added.
+    expect(seen[0]).toEqual({ type: 'host/session-added', sessionId: id, blank: true, cwd: '/tmp/fixture' })
+    expect(seen[1]).toMatchObject({
+      type: 'host/workspace-changed',
+      workspace: { workspaceId: 'fx-ws-fixture', sessionIds: [id, 'fx-alpha', 'fx-beta', 'fx-gamma'] },
+    })
+  })
+
+  it('supports an empty baseline, preallocated ids, workspace-first frames, and idempotent retry', async () => {
+    const api = createFixtureApi({ empty: true, createFrameOrder: 'workspace-first' })
+    const initialSessions = await api.sessions.list(req({}))
+    const initialWorkspaces = await api.workspace.list(req({}))
+    expect(initialSessions.result).toMatchObject({ ok: true, value: { items: [] } })
+    expect(initialWorkspaces.result).toMatchObject({ ok: true, value: { items: [] } })
+
+    const made = await api.workspace.create(req({ name: 'nova' }))
+    if (!made.result.ok) throw new Error('workspace create failed')
+    const abort = new AbortController()
+    const framesPromise = collect(api.events.host(req({}), abort.signal), abort, frames => frames.length === 2)
+    await new Promise(resolve => setTimeout(resolve, 10))
+    const preallocated = sid('fx-preallocated')
+    const created = await api.sessions.create(req({
+      workspaceId: made.result.value.workspace.workspaceId,
+      sessionId: preallocated,
+    }))
+    expect(created.result).toEqual({ ok: true, value: { sessionId: preallocated } })
+    const frames = await framesPromise
+    expect(frames[0]).toMatchObject({
+      type: 'host/workspace-changed', workspace: { sessionIds: [preallocated] },
+    })
+    expect(frames[1]).toEqual({ type: 'host/session-added', sessionId: preallocated, blank: true, cwd: made.result.value.workspace.path })
+
+    const retried = await api.sessions.create(req({
+      workspaceId: made.result.value.workspace.workspaceId,
+      sessionId: preallocated,
+    }))
+    expect(retried.result).toEqual({ ok: true, value: { sessionId: preallocated } })
+    const listed = await api.sessions.list(req({}))
+    if (!listed.result.ok) throw new Error('session list failed')
+    expect(listed.result.value.items.filter(item => item.sessionId === preallocated)).toHaveLength(1)
+
+    const conflict = await api.sessions.create(req({ sessionId: preallocated, cwd: '/elsewhere' }))
+    expect(conflict.result).toMatchObject({
+      ok: false,
+      error: { code: 'session-conflict', details: { sessionId: preallocated, requestedCwd: '/elsewhere' } },
+    })
+  })
+
+  it('attaches an existing ungrouped Session to a matching Workspace', async () => {
+    const api = createFixtureApi()
+    const sessionId = sid('fx-existing-ungrouped')
+    await expect(api.sessions.create(req({ sessionId, cwd: '/tmp/fixture' }))).resolves.toMatchObject({
+      result: { ok: true, value: { sessionId } },
+    })
+
+    await expect(api.sessions.create(req({
+      sessionId,
+      workspaceId: 'fx-ws-fixture' as WorkspaceId,
+    }))).resolves.toMatchObject({ result: { ok: true, value: { sessionId } } })
+
+    const workspaces = await api.workspace.list(req({}))
+    if (!workspaces.result.ok) throw new Error('workspace list failed')
+    expect(workspaces.result.value.items[0]?.sessionIds).toContain(sessionId)
+  })
+
+  it('reports a conflict without an existing cwd detail for an unrecorded cwd', async () => {
+    const api = createFixtureApi()
+    const listed = await api.sessions.list(req({}))
+    if (!listed.result.ok) throw new Error('session list failed')
+    const existing = listed.result.value.items.find(item => item.sessionId === sid('fx-alpha'))
+    if (existing === undefined) throw new Error('fixture Session missing')
+    delete existing.cwd
+
+    const conflict = await api.sessions.create(req({ sessionId: existing.sessionId }))
+    expect(conflict.result).toEqual({
+      ok: false,
+      error: {
+        code: 'session-conflict',
+        message: `session ${existing.sessionId} already uses no cwd`,
+        details: { sessionId: existing.sessionId, requestedCwd: '/tmp/fixture' },
+      },
+    })
+  })
+
+  it('publishes an ungrouped Session when Workspace attachment fails', async () => {
+    const api = createFixtureApi({ failWorkspaceAttach: true })
+    const sessionId = sid('fx-partial')
+    const created = await api.sessions.create(req({
+      workspaceId: 'fx-ws-fixture' as WorkspaceId,
+      sessionId,
+    }))
+    expect(created.result).toMatchObject({
+      ok: false,
+      error: { code: 'workspace-attach-failed', details: { sessionId, workspaceId: 'fx-ws-fixture' } },
+    })
+    const listed = await api.sessions.list(req({}))
+    const workspaces = await api.workspace.list(req({}))
+    if (!listed.result.ok || !workspaces.result.ok) throw new Error('list failed')
+    expect(listed.result.value.items.filter(item => item.sessionId === sessionId)).toHaveLength(1)
+    expect(workspaces.result.value.items[0]?.sessionIds).not.toContain(sessionId)
+
+    const retried = await api.sessions.create(req({
+      workspaceId: 'fx-ws-fixture' as WorkspaceId,
+      sessionId,
+    }))
+    expect(retried.result).toMatchObject({ ok: false, error: { code: 'workspace-attach-failed' } })
+    const afterRetry = await api.sessions.list(req({}))
+    if (!afterRetry.result.ok) throw new Error('list failed')
+    expect(afterRetry.result.value.items.filter(item => item.sessionId === sessionId)).toHaveLength(1)
+  })
+
+  it('reconciles a dropped create response and can reject a prompt before acceptance', async () => {
+    const sessionId = sid('fx-lost-response')
+    const dropped = createFixtureApi({ dropSessionCreateResponse: true })
+    await expect(Promise.resolve().then(() => dropped.sessions.create(req({
+      workspaceId: 'fx-ws-fixture' as WorkspaceId,
+      sessionId,
+    })))).rejects.toThrow(/dropped session\.create response/)
+    const listed = await dropped.sessions.list(req({}))
+    const workspaces = await dropped.workspace.list(req({}))
+    if (!listed.result.ok || !workspaces.result.ok) throw new Error('list failed')
+    expect(listed.result.value.items.some(item => item.sessionId === sessionId)).toBe(true)
+    expect(workspaces.result.value.items[0]?.sessionIds).toContain(sessionId)
+    await expect(dropped.sessions.create(req({
+      workspaceId: 'fx-ws-fixture' as WorkspaceId,
+      sessionId,
+    }))).resolves.toMatchObject({ result: { ok: true, value: { sessionId } } })
+
+    const rejecting = createFixtureApi({ empty: true, rejectPrompt: true })
+    const real = await rejecting.sessions.create(req({ sessionId: sid('fx-rejected') }))
+    if (!real.result.ok) throw new Error('session create failed')
+    const prompt = await rejecting.sessions.prompt(req({
+      sessionId: real.result.value.sessionId,
+      mode: 'queue' as const,
+      content: [{ type: 'text' as const, text: 'keep me' }],
+    }))
+    expect(prompt.result).toMatchObject({ ok: false, error: { code: 'agent-busy' } })
   })
 
   it('timing hooks: history delay + one-shot failure, silent append, and breakStreams end open generators', async () => {
@@ -248,10 +619,15 @@ describe('createFixtureApi', () => {
     await new Promise(resolve => setTimeout(resolve, 10))
     hooks.appendSilent('fx-alpha', '静默丢帧')
     hooks.appendUser('fx-alpha', '正常直播')
+    hooks.appendTitle('fx-alpha', 'Fixture 修订标题')
     await vi.waitFor(() => {
       expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('正常直播'))).toBe(true)
+      expect(seen.some(f => f.type === 'session/projection' && f.key === 'title' && f.value === 'Fixture 修订标题')).toBe(true)
     })
     expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('静默丢帧'))).toBe(false)
+    const rawTitleIndex = seen.findIndex(f => f.type === 'session/event' && (f.event as { type: string }).type === 'session/title')
+    const titleControlIndex = seen.findIndex(f => f.type === 'session/projection' && f.key === 'title' && f.value === 'Fixture 修订标题')
+    expect(titleControlIndex).toBe(rawTitleIndex + 1)
     // But history serves the silent event (the client's repull finds it).
     const repull = await api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 5 }))
     if (!repull.result.ok) throw new Error('repull failed')
@@ -273,6 +649,7 @@ describe('createFixtureApi', () => {
 describe('FixtureApiClient (protocol-level fake carrier)', () => {
   afterEach(() => {
     vi.restoreAllMocks()
+    vi.unstubAllGlobals()
   })
 
   it('doFetch is an unreachable tripwire (all protocol paths overridden)', () => {
@@ -308,9 +685,66 @@ describe('FixtureApiClient (protocol-level fake carrier)', () => {
     expect((await client.sessions.prompt({ sessionId: id, mode: 'queue', content: [{ type: 'text', text: '嗨' }] })).result.ok).toBe(true)
     expect((await client.sessions.cancel({ sessionId: id })).result.ok).toBe(true)
     expect((await client.host.describe({})).result.ok).toBe(true)
-    const goal = await client.goals.get({ sessionId: sid('fx-alpha') })
-    expect(goal.result).toMatchObject({ ok: true, value: { goal: { objective: 'Ship the fixture goal bar' } } })
-    expect((await client.goals.get({ sessionId: id })).result).toEqual({ ok: true, value: { goal: null } })
+    expect((await client.workspace.list({})).result.ok).toBe(true)
+    const workspace = await client.workspace.create({ name: 'via-client' })
+    if (!workspace.result.ok) throw new Error('workspace create failed')
+    expect(workspace.result.value.workspace.title).toBe('via-client')
+    const wsid = workspace.result.value.workspace.workspaceId
+    const renamed = await client.workspace.rename({ workspaceId: wsid, title: 'via-client-2' })
+    if (!renamed.result.ok) throw new Error('workspace rename failed')
+    expect(renamed.result.value.workspace.title).toBe('via-client-2')
+    const attached = await client.sessions.create({ workspaceId: wsid })
+    if (!attached.result.ok) throw new Error('attached create failed')
+    const moved = await client.workspace.insertSessionBefore({ workspaceId: wsid, sessionId: attached.result.value.sessionId })
+    if (!moved.result.ok) throw new Error('workspace move failed')
+    expect(moved.result.value.workspace.sessionIds).toEqual([attached.result.value.sessionId])
+  })
+
+  it('maps empty, prompt-reject, and workspace-first query scenarios', async () => {
+    vi.stubGlobal('location', {
+      search: '?fixture=empty&fixturePrompt=reject&fixtureFrames=workspace-first',
+    })
+    const client = new FixtureApiClient()
+    await expect(client.sessions.list({})).resolves.toMatchObject({ result: { ok: true, value: { items: [] } } })
+    const made = await client.workspace.create({ name: 'query-workspace' })
+    if (!made.result.ok) throw new Error('workspace create failed')
+    const abort = new AbortController()
+    const framesPromise = collect(client.events.host({}, abort.signal), abort, frames => frames.length === 2)
+    await new Promise(resolve => setTimeout(resolve, 10))
+    const sessionId = sid('fx-query-session')
+    const created = await client.sessions.create({
+      workspaceId: made.result.value.workspace.workspaceId,
+      sessionId,
+    })
+    expect(created.result).toMatchObject({ ok: true, value: { sessionId } })
+    const frames = await framesPromise
+    expect(frames.map(frame => frame.type)).toEqual(['host/workspace-changed', 'host/session-added'])
+    const rejected = await client.sessions.prompt({
+      sessionId,
+      mode: 'queue',
+      content: [{ type: 'text', text: 'retain' }],
+    })
+    expect(rejected.result).toMatchObject({ ok: false, error: { code: 'agent-busy' } })
+  })
+
+  it('maps attach-failure and dropped-response query scenarios', async () => {
+    vi.stubGlobal('location', { search: '?fixture&fixtureAttach=fail' })
+    const partial = new FixtureApiClient()
+    const partialResult = await partial.sessions.create({
+      workspaceId: 'fx-ws-fixture' as WorkspaceId,
+      sessionId: sid('fx-query-partial'),
+    })
+    expect(partialResult.result).toMatchObject({
+      ok: false,
+      error: { code: 'workspace-attach-failed', details: { sessionId: 'fx-query-partial' } },
+    })
+
+    vi.stubGlobal('location', { search: '?fixture&fixtureSessionCreate=drop-response' })
+    const dropped = new FixtureApiClient()
+    await expect(dropped.sessions.create({
+      workspaceId: 'fx-ws-fixture' as WorkspaceId,
+      sessionId: sid('fx-query-dropped'),
+    })).rejects.toThrow(/dropped session\.create response/)
     const ref = { id: 'fx-goal-1' as never, revision: 1 }
     expect((await client.goals.create({ sessionId: id, objective: 'x' })).result.ok).toBe(false)
     expect((await client.goals.edit({ sessionId: id, ref, objective: 'x' })).result.ok).toBe(false)

packages/client/connection/tests/http-bridge.spec.ts

@@ -0,0 +1,47 @@
+import { EventEmitter } from 'node:events'
+import { Readable } from 'node:stream'
+import type { IncomingMessage, ServerResponse } from 'node:http'
+import { describe, expect, it } from 'vitest'
+import { bridge } from '../src/http-bridge.ts'
+
+describe('HTTP bridge abort', () => {
+  it('aborts a pending native picker request when the browser disconnects', async () => {
+    const body = JSON.stringify({
+      type: 'client-request', rpcId: 'picker-1', method: 'host.pickDirectory', payload: {},
+    })
+    const request = Readable.from([Buffer.from(body)]) as unknown as IncomingMessage
+    Object.assign(request, {
+      url: '/api/host.pickDirectory',
+      method: 'POST',
+      headers: { 'content-type': 'application/json' },
+    })
+
+    const response = Object.assign(new EventEmitter(), {
+      writableEnded: false,
+      writeHead() { return this },
+      write() { return true },
+      end() { this.writableEnded = true; return this },
+    }) as unknown as ServerResponse
+
+    let resolveStarted!: () => void
+    const started = new Promise<void>((resolve) => { resolveStarted = resolve })
+    let carrierSignal: AbortSignal | undefined
+    const pending = bridge(request, response, {
+      fetch: async (input) => {
+        const fetchRequest = input as Request
+        carrierSignal = fetchRequest.signal
+        resolveStarted()
+        if (!fetchRequest.signal.aborted) {
+          await new Promise<void>((resolve) => {
+            fetchRequest.signal.addEventListener('abort', () => { resolve() }, { once: true })
+          })
+        }
+        return Response.json({ aborted: fetchRequest.signal.aborted })
+      },
+    })
+    await started
+    response.emit('close')
+    await pending
+    expect(carrierSignal?.aborted).toBe(true)
+  })
+})

packages/client/connection/tests/native-dialog-request.spec.ts

@@ -0,0 +1,57 @@
+import type { IncomingHttpHeaders } from 'node:http'
+import { describe, expect, it } from 'vitest'
+import { isTrustedNativeDialogRequest } from '../src/native-dialog-request.ts'
+
+function request(
+  remoteAddress: string | undefined,
+  headers: IncomingHttpHeaders = {
+    host: '127.0.0.1:3080',
+    origin: 'http://127.0.0.1:3080',
+    'sec-fetch-site': 'same-origin',
+  },
+) {
+  return { socket: { remoteAddress }, headers }
+}
+
+describe('native dialog request trust', () => {
+  it('accepts loopback same-origin browser requests', () => {
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1'))).toBe(true)
+    expect(isTrustedNativeDialogRequest(request('::1', {
+      host: '[::1]:3080', origin: 'http://[::1]:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(true)
+    expect(isTrustedNativeDialogRequest(request('::ffff:127.0.0.1'))).toBe(true)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      host: 'localhost:3080', origin: 'http://localhost:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(true)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.2', {
+      host: '127.0.0.2:3080', origin: 'https://127.0.0.2:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(true)
+  })
+
+  it('rejects remote sockets and requests without matching browser metadata', () => {
+    expect(isTrustedNativeDialogRequest(request('192.168.1.5'))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request(undefined))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      host: '127.0.0.1:3080', origin: 'http://evil.example', 'sec-fetch-site': 'cross-site',
+    }))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      host: '127.0.0.1:3080', origin: 'http://localhost:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', { host: '127.0.0.1:3080' }))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      origin: 'http://127.0.0.1:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      host: 'attacker.example:3080', origin: 'http://attacker.example:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      host: '127.0.0.1:3080', origin: 'ftp://127.0.0.1:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      host: '127.999.0.1:3080', origin: 'http://127.999.0.1:3080', 'sec-fetch-site': 'same-origin',
+    }))).toBe(false)
+    expect(isTrustedNativeDialogRequest(request('127.0.0.1', {
+      host: '[invalid', origin: 'http://[invalid', 'sec-fetch-site': 'same-origin',
+    }))).toBe(false)
+  })
+})

packages/client/connection/tests/node-half.spec.ts

@@ -1,10 +1,53 @@
-/** Node half: the empty host apply (Loader governance + dshClient discovery placeholder). */
+/** Node half: registers the /api prefix route bridging to the api gateway. */
+import { Context } from 'cordis'
 import { describe, expect, it } from 'vitest'
-import { apply } from '../src/index.ts'
+import type { IncomingMessage, ServerResponse } from 'node:http'
+import type { ApiProxy } from '@deepseek-ai/dsh-host-apiproxy/api'
+import type { HttpServerService, WebRoute } from '@deepseek-ai/dsh-host-webserver'
+import { API_PATH, apply, inject } from '../src/index.ts'
 
-describe('node half', () => {
-  it('apply is a no-op host placeholder', () => {
-    apply(undefined)
-    expect(true).toBe(true) // reaching here without throw is the contract
+describe('connection node half', () => {
+  it('registers the /api prefix route and removes it with the fiber', async () => {
+    const ctx = new Context()
+    const routes: WebRoute[] = []
+    // Structural fake: the plugin only touches register(); the service class
+    // carries private state a literal cannot (and need not) reproduce.
+    const httpServer: Pick<HttpServerService, 'register' | 'tapIndex' | 'port'> = {
+      register(route) {
+        routes.push(route)
+        return () => { routes.splice(routes.indexOf(route), 1) }
+      },
+      tapIndex: () => () => {},
+      port: 0,
+    }
+    ctx.provide('httpServer', httpServer as HttpServerService)
+    ctx.provide('apiProxy', {} as unknown as ApiProxy)
+
+    const fiber = ctx.plugin({ inject: [...inject], apply })
+    await fiber.await()
+    expect(routes).toHaveLength(1)
+    expect(routes[0]).toMatchObject({ kind: 'prefix', path: API_PATH })
+
+    for (const url of ['/api/host.pickDirectory', '/api/host.openPath']) {
+      let status: number | undefined
+      let body: unknown
+      const deniedRequest = {
+        url,
+        headers: {
+          host: 'harness.example', origin: 'http://harness.example', 'sec-fetch-site': 'same-origin',
+        },
+        socket: { remoteAddress: '192.168.1.8' },
+      } as unknown as IncomingMessage
+      const deniedResponse = {
+        writeHead(value: number) { status = value; return this },
+        end(value?: unknown) { body = value; return this },
+      } as unknown as ServerResponse
+      await routes[0]!.handler(deniedRequest, deniedResponse)
+      expect(status).toBe(403)
+      expect(body).toBe('forbidden')
+    }
+
+    await fiber.dispose()
+    expect(routes).toHaveLength(0)
   })
 })

packages/client/connection/tsconfig.json

@@ -1,14 +1,9 @@
 {
-  "extends": "../../../tsconfig.base.json",
+  "extends": "../../../tsconfig.base.client.json",
   "compilerOptions": {
     "rootDir": "src",
     "outDir": "lib/types",
-    "lib": [
-      "ES2024",
-      "DOM",
-      "DOM.Iterable"
-    ],
-    "types": []
+    "types": ["node"]
   },
   "include": [
     "src"
@@ -20,12 +15,18 @@
     {
       "path": "../../core/session"
     },
+    {
+      "path": "../../ui/commands"
+    },
     {
       "path": "../../util/brand"
     },
     {
       "path": "../../host/apiproxy"
     },
+    {
+      "path": "../../host/webserver"
+    },
     {
       "path": "../../ui/user-approval"
     },

packages/client/hmr/README.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+README.md: 2b2f63c25cbf3a46babef78a4dfb52f859156887
+README.zh.md: 6d94ca4a5e91f390e58575aa4ddf64fc18a509de

packages/client/hmr/README.md

@@ -0,0 +1,21 @@
+# @deepseek-ai/dsh-client-hmr
+
+English | [中文](README.zh.md)
+
+Hot reload for fetch-arrival client plugins. A static-arrival entry composed only into `--dev` graphs (`dsh web --dev`); production graphs omit the row, so the shell-bundled code stays inert.
+
+The browser half subscribes to the system SSE channel (`GET /plugins/events`) and reloads one plugin per `rebuilt` frame, serialized through a queue (the bundle handoff slot is single). The sequence per frame — `prefetch` (fetch the new bundle before touching anything), `invalidate`, `registry.delete` (before the fiber: a bare fiber dispose trips the vendored Loader's self-dispose branch, which would mark the entry disabled), drain the old fiber, delete `entry.fiber`, remove owned `<style data-plugin>` tags, `entry.refresh()` re-imports and remounts, `fiber.await()` rethrows startup failures loud. Dependents reload through cordis itself: a fiber's activation epoch strings its service providers' uids, so replacing a provider's fiber cascades every dependent with zero client-side graph analysis. The node half detects rebuilds with one interval that stat-polls each graph bundle from a synchronous baseline, immediately re-hashes after adding a row, retains missing rows as dirty, and broadcasts only real rev changes; any tsdown watch process producing the bundle therefore triggers HMR with no builder→host channel.
+
+## Model Experience
+
+None, as the reload driver is browser-side machinery; nothing here reaches a model request.
+
+#### KV Cache effect
+
+None; this package neither assembles nor sends a provider request.
+
+## Known Limitations and Deferred Work
+
+- **Reload is coarse by design** — a fresh fiber and fresh components; React state inside the reloaded plugin is lost while the data layer (connection/runtime fibers, Session objects) is untouched. react-refresh-grade state preservation conflicts with "re-executing the bundle re-runs the factory" and is deliberately out.
+- **No failure rollback** — a reload that fails leaves the entry FAILED and loud in the loader status projection; restoring the previous bundle automatically is deferred until a real need shows.
+- **Graph rev is not refreshed by rebuilt frames** — the stale rev is harmless (the bundle endpoint serves no-cache); rev refresh lands with the reconnect-handshake mechanism.

packages/client/hmr/README.zh.md

@@ -0,0 +1,21 @@
+# @deepseek-ai/dsh-client-hmr
+
+[English](README.md) | 中文
+
+为通过 fetch 到达的客户端插件提供热重载。该静态到达配置项只组合进 `--dev` 图（`dsh web --dev`）；生产图省略此行，因此外壳打包的代码保持不活动。
+
+浏览器侧订阅系统 SSE 通道（`GET /plugins/events`），每个 `rebuilt` 帧重载一个插件，并通过队列串行执行（组合包交接 slot 只能容纳一个）。每帧的顺序是：`prefetch`（在触碰任何内容前抓取新组合包）、`invalidate`、`registry.delete`（在 fiber 之前执行：只释放 fiber 会触发 vendored Loader 的 self-dispose 分支，把配置项标为禁用）、排空旧 fiber、删除 `entry.fiber`、移除自身拥有的 `<style data-plugin>` 标签、通过 `entry.refresh()` 重新导入并挂载、以 `fiber.await()` 将启动失败高声重新抛出。依赖方由 cordis 自身重载：fiber 的激活 epoch 会串联其服务提供方的 uid，因此替换提供方 fiber 会级联所有依赖方，无需客户端图分析。node 侧使用一个 interval 检测重建：从同步基线开始 stat-poll 每个图组合包；新增一行后立即重新计算 hash；缺失行保持 dirty；只广播真实 rev 变更。因此，任何生成组合包的 tsdown watch 进程都能触发 HMR，无需 builder→host 通道。
+
+## 模型体验
+
+无。重载驱动器属于浏览器侧机制；这里没有任何内容进入模型请求。
+
+#### KV Cache 影响
+
+无；该包既不组装也不发送提供方请求。
+
+## 已知限制与暂缓事项
+
+- **重载有意保持粗粒度**：会创建全新的 fiber 和组件；重载插件中的 React 状态会丢失，数据层（connection/runtime fiber、Session 对象）不受影响。react-refresh 级状态保留与「重新执行组合包会重新运行 factory」冲突，因此有意排除。
+- **失败时不回滚**：失败的重载会使配置项处于 FAILED 状态，并在 loader 状态投影中高声报告；自动恢复先前组合包会等到实际需要出现后再实现。
+- **重建帧不会刷新图 rev**：陈旧 rev 无害（组合包端点以 no-cache 提供内容）；rev 刷新会随重新连接握手机制落地。

packages/client/hmr/package.json

@@ -0,0 +1,56 @@
+{
+  "name": "@deepseek-ai/dsh-client-hmr",
+  "description": "Dev-only hot-reload driver for fetch-arrival client entries: SSE rebuilt frames → prefetch/invalidate → fiber swap through the vendored Loader entry",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./client": {
+      "types": "./lib/types/client/index.d.ts",
+      "default": "./lib/client.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "dshClient": {
+    "inject": [],
+    "platform": "web",
+    "immediately": true
+  },
+  "license": "BSD-3-Clause",
+  "dependencies": {
+    "schemastery": "^3.18.0"
+  },
+  "peerDependencies": {
+    "@cordisjs/plugin-loader": "^1.0.0-rc.5",
+    "@deepseek-ai/dsh-client-modules": "^0.0.1",
+    "@deepseek-ai/dsh-host-webserver": "^0.0.1",
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "cordis": "^4.0.0-rc.7"
+  },
+  "devDependencies": {
+    "@cordisjs/plugin-loader": "workspace:^",
+    "@deepseek-ai/dsh-client-modules": "workspace:^",
+    "@deepseek-ai/dsh-host-webserver": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "cordis": "^4.0.0-rc.7"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/client.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ]
+}

packages/client/hmr/src/client/index.ts

@@ -0,0 +1,182 @@
+/**
+ * client-hmr, browser half: hot-reload driver for client plugin entries.
+ *
+ * Listens on the host's system SSE channel (`GET /plugins/events`); on a
+ * `rebuilt` frame it re-fetches the entry's bundle and swaps the cordis
+ * fiber in place. Every graph entry is a plugin bundle under the web2 model
+ * — `immediately` rows differ only in stage-one prefetch (a boot
+ * optimization), so all rostered plugin packages share these reload semantics;
+ * normal packages (react family, cordis, shell, pure libs) are not entries
+ * and shell changes still mean a page reload. Cascade is zero-touch:
+ * downstream fibers key their activation epoch on provider fiber uids
+ * (vendor/cordis/src/fiber.ts `_refresh`), so replacing a provider fiber
+ * re-cascades natively — reloading a data-layer plugin (connection/runtime)
+ * cascades into its UI dependents with no HMR-side bookkeeping.
+ *
+ * Reload order (lazy CJS table): invalidate (drop the stale factory and
+ * materialized record) → prefetch (fetch + execute + register the fresh
+ * factory) → registry-first teardown → drain old fiber unload → remove
+ * owned `<style data-plugin>` tags → `entry.refresh()` materializes the new
+ * factory. Invalidate MUST precede prefetch: a live factory makes prefetch
+ * a no-op, and re-executing a bundle over an undeleted registration is a
+ * loud duplicate. The swap is safe because execution is pure registration
+ * under the lazy model — every module side effect (CSS injection included)
+ * lives in the factory closure and runs at materialization, inside
+ * refresh(). That also keeps the CSS ordering guarantee: owned styles are
+ * removed after the old fiber's disposers drained (SlotCore one-owner
+ * unregister) and before materialization re-injects tags under the same
+ * stable tag ids.
+ *
+ * Failure window: if prefetch rejects after invalidate, the module is left
+ * unregistered while the OLD fiber keeps running untouched (teardown never
+ * started) — degraded but recoverable, the next rebuilt frame retries from
+ * scratch. Consistent with the v1 no-rollback policy below. Known dev-only
+ * race: a rebuilt frame overlapping a still-in-flight boot arrival shares
+ * that arrival's task and may materialize the pre-rebuild bytes; the next
+ * rebuilt frame self-heals.
+ *
+ * Why not the naive `entry.fiber.dispose()` → `entry.refresh()` path —
+ * confirmed against vendor sources:
+ * 1. `Entry.fiber` is never cleared on dispose (vendor/loader/src/config/
+ *    entry.ts assigns it only in `_init`), so `refresh()` hits its
+ *    `if (this.fiber) return` guard and no-ops.
+ * 2. A bare `fiber.dispose()` lands in Loader's self-dispose branch
+ *    (vendor/loader/src/index.ts `internal/plugin` case 4: the registry
+ *    still holds the runtime at emit time), which flags the entry
+ *    `disabled: true` — permanently.
+ * vendor/hmr's reload skeleton documents the fix: delete the runtime record
+ * FIRST (`registry.delete` → case 4 returns early, the entry stays enabled),
+ * then rebuild. We additionally clear `entry.fiber` ourselves so
+ * `entry.refresh()` re-imports and re-plugins through the Loader's own
+ * `_init` (entry-resolved config, automatic `fiber.entry` rebinding) instead
+ * of hand-rolling `registry.plugin`. Client entries have exactly one fiber
+ * per runtime, so `registry.delete` never collaterally disposes siblings.
+ *
+ * Self-reload: this plugin is itself a graph entry, so a rebuilt frame may
+ * name it. The in-flight reload keeps running in the old bundle's closure
+ * (its EventSource closes with the old fiber's effects); the new bundle's
+ * apply opens a fresh channel. Frames arriving during the gap are lost —
+ * acceptable for the dev channel, the next rebuild renotifies.
+ *
+ * Failure policy (v1): no rollback. An import failure leaves the entry
+ * fiberless (the next rebuilt frame retries from scratch); an apply failure
+ * leaves a FAILED fiber for the shell's status projection. Both log loudly.
+ */
+import type { Context } from 'cordis'
+import type { Entry, Loader } from '@cordisjs/plugin-loader'
+import type { PluginsEventFrame } from '../events.ts'
+import { EVENTS_ENDPOINT } from '../events.ts'
+
+export type { PluginsEventFrame } from '../events.ts'
+export { EVENTS_ENDPOINT } from '../events.ts'
+
+/** Cordis plugin name. */
+export const name = 'client-hmr'
+
+/** Required services: the vendored Loader (entry governance) and the client module system (boot provide, service name `modules`). */
+export const inject = ['loader', 'modules']
+
+/** Find the loader entry whose module specifier is `id` (entry tree ids are random; the package name lives in `options.name`). */
+function findEntry(loader: Loader, id: string): Entry | undefined {
+  for (const entry of loader.entries()) {
+    if (entry.options.name === id) return entry
+  }
+  return undefined
+}
+
+/** Remove every `<style data-plugin>` tag owned by `id` (attribute compared verbatim — no CSS-selector escaping pitfalls). */
+function removeOwnedStyles(id: string): void {
+  for (const el of document.querySelectorAll('style[data-plugin]')) {
+    if (el.getAttribute('data-plugin') === id) el.remove()
+  }
+}
+
+/**
+ * Mount the HMR driver: subscribe to the system SSE channel and hot-swap
+ * rebuilt entries.
+ * @param ctx - plugin context with `loader` and `modules` available.
+ */
+export function apply(ctx: Context): void {
+  // Both are declared injections (typed Context merges: `modules` from the
+  // client module loader package, `loader` from the vendored Loader).
+  const modLoader = ctx.modules
+  const loader: Loader = ctx.loader
+
+  async function reload(id: string): Promise<void> {
+    const entry = findEntry(loader, id)
+    if (entry === undefined) {
+      ctx.logger.warn(`client-hmr: rebuilt frame for unknown entry "${id}" (not in the loader tree)`)
+      return
+    }
+    // Invalidate first (drop stale factory + record — a live factory makes
+    // prefetch a no-op and re-registration a loud duplicate), then run the
+    // async half while the old fiber still serves: fetch + execute registers
+    // the fresh factory with zero side effects (lazy CJS — module bodies run
+    // at materialization, not execution).
+    modLoader.invalidate(id)
+    await modLoader.prefetch(id)
+
+    const oldFiber = entry.fiber
+    if (oldFiber !== undefined) {
+      // Registry-first teardown (see module comment): the runtime record must
+      // be gone before the fiber's disposer emits internal/plugin, or the
+      // Loader flags the entry disabled.
+      const runtime = oldFiber.runtime
+      if (runtime !== null) entry.ctx.registry.delete(runtime.callback)
+      // Drain the unload: effect disposers (slots, subscriptions) must finish
+      // before the new bundle executes and the new apply re-registers.
+      while (oldFiber.inertia !== undefined) await oldFiber.inertia
+      delete entry.fiber
+    }
+    // Old owned styles go before materialization re-injects them (the CSS
+    // idempotency guard keys on stable tag ids).
+    removeOwnedStyles(id)
+    // Re-init through the entry: fiber cleared above, so refresh() re-imports
+    // — materializing the prefetched factory (CSS injects here) — and
+    // re-plugins under the entry context. Import failures are logged by
+    // Entry._init and leave the entry fiberless (retryable).
+    await entry.refresh()
+    // Surface apply failures loudly (v1: no rollback, FAILED state stays).
+    await entry.fiber?.await()
+  }
+
+  // Serialize reloads: frames can arrive faster than a swap completes, and
+  // interleaved dispose/execute chains would corrupt the single-slot handoff.
+  let queue: Promise<void> = Promise.resolve()
+  const handle = (frame: PluginsEventFrame): void => {
+    switch (frame.type) {
+      case 'rebuilt':
+        queue = queue.then(() => reload(frame.id)).catch((error: unknown) => {
+          ctx.logger.error(`client-hmr: reload of "${frame.id}" failed`)
+          ctx.logger.error(error)
+        })
+        break
+      case 'graph':
+        // Connect-time snapshot, unused in v1. The loader's cached graph rev
+        // goes stale after rebuilds — harmless, since prefetch hits the
+        // network anyway (host serves bundles no-cache); graph rev refresh
+        // lands with the reconnect-handshake mechanism.
+        break
+      default:
+        // Merge-extensible frame union: unknown frame types from newer hosts
+        // are ignored by design.
+        break
+    }
+  }
+
+  ctx.effect(() => {
+    const source = new EventSource(EVENTS_ENDPOINT)
+    source.addEventListener('message', (event: MessageEvent<string>) => {
+      let frame: PluginsEventFrame
+      try {
+        frame = JSON.parse(event.data) as PluginsEventFrame
+      } catch {
+        // Wire boundary: a malformed dev-channel frame is dropped loudly.
+        ctx.logger.warn(`client-hmr: unparseable event frame: ${event.data}`)
+        return
+      }
+      handle(frame)
+    })
+    return () => { source.close() }
+  }, 'client-hmr: event source')
+}

packages/client/hmr/src/events.ts

@@ -0,0 +1,16 @@
+/**
+ * Wire protocol of the `/plugins/events` dev SSE channel — single source for
+ * both halves of this package. Frames still cross a wire boundary: the
+ * browser half validates them at its JSON parse point; sharing the type keeps
+ * the two ends from drifting, not from parsing.
+ */
+
+import type { WebBootGraph } from '@deepseek-ai/dsh-client-modules'
+
+/** One SSE frame: the full graph on connect, or one rebuilt bundle notice. */
+export type PluginsEventFrame =
+  | { type: 'graph'; graph: WebBootGraph }
+  | { type: 'rebuilt'; id: string; rev: string }
+
+/** System SSE endpoint pushing graph/rebuilt frames (wire protocol constant). */
+export const EVENTS_ENDPOINT = '/plugins/events'

packages/client/hmr/src/index.ts

@@ -0,0 +1,189 @@
+/**
+ * HMR plugin, node half: the host end of the dev reload chain. One interval
+ * stat-polls every graph row's client bundle (polling by design: network
+ * mounts deliver no inotify events), reports content changes through
+ * `clientModuleHost.rebuilt(id)`, and serves the `/plugins/events` SSE channel
+ * broadcasting graph/rebuilt frames to the browser half (src/client/).
+ * Dev-only row: prod compositions never mount this plugin.
+ */
+import { statSync } from 'node:fs'
+import type { ServerResponse } from 'node:http'
+import type { Context } from 'cordis'
+import z from 'schemastery'
+// Empty type imports carry the clientModuleHost/httpServer Context merges.
+import type {} from '@deepseek-ai/dsh-client-modules'
+import type {} from '@deepseek-ai/dsh-host-webserver'
+import type { PluginsEventFrame } from './events.ts'
+import { EVENTS_ENDPOINT } from './events.ts'
+
+export type { PluginsEventFrame } from './events.ts'
+export { EVENTS_ENDPOINT } from './events.ts'
+
+/** Cordis plugin name. */
+export const name = 'client-hmr'
+
+/** Required services: the web plugin table and the route registry. */
+export const inject = ['clientModuleHost', 'httpServer']
+
+/** Plugin config, validated by the same-named schemastery schema. */
+export interface Config {
+  /** Bundle stat-poll interval in milliseconds (default 500, the build-side watcher's polling default). */
+  pollIntervalMs?: number
+}
+
+export const Config: z<Config> = z.object({
+  pollIntervalMs: z.number().step(1).min(1).default(500),
+})
+
+/** Serialize one frame as an SSE data line. */
+function sseData(frame: PluginsEventFrame): string {
+  return `data: ${JSON.stringify(frame)}\n\n`
+}
+
+interface WatchedBundle {
+  path: string
+  mtimeMs: number
+  size: number
+  dirty: boolean
+}
+
+/**
+ * Mount the dev chain: bundle watches, rebuilt reporting, and the SSE channel.
+ * @param ctx - host plugin context carrying clientModuleHost and httpServer.
+ * @param config - validated {@link Config}.
+ */
+export function apply(ctx: Context, config: Config): void {
+  // schemastery's .default() guarantees the field is set after validation.
+  const pollIntervalMs = config.pollIntervalMs as number
+
+  // --- bundle watch: one HMR-owned stat poll ------------------------------
+  const watched = new Map<string, WatchedBundle>()
+
+  const rehash = (id: string, watch: WatchedBundle, current: { mtimeMs: number; size: number }): void => {
+    try {
+      // rebuilt() re-hashes; an unchanged hash stays silent (clientModuleHost
+      // fires onRebuilt only on a real rev change).
+      ctx.clientModuleHost.rebuilt(id)
+    } catch (error) {
+      const code = (error as NodeJS.ErrnoException).code
+      if (code === 'ENOENT') {
+        watch.dirty = true
+        return
+      }
+      ctx.logger.warn(error)
+    }
+    watch.mtimeMs = current.mtimeMs
+    watch.size = current.size
+    watch.dirty = false
+  }
+
+  const watchRow = (id: string, path: string): void => {
+    let baseline: { mtimeMs: number; size: number }
+    try {
+      baseline = statSync(path)
+    } catch (error) {
+      watched.set(id, { path, mtimeMs: 0, size: 0, dirty: true })
+      if ((error as NodeJS.ErrnoException).code !== 'ENOENT') ctx.logger.warn(error)
+      return
+    }
+    const watch = { path, mtimeMs: baseline.mtimeMs, size: baseline.size, dirty: false }
+    watched.set(id, watch)
+    // The module host hashed before publishing the graph. Re-hash immediately
+    // after capturing this baseline so a write in between cannot become an
+    // already-current baseline paired with a stale graph rev.
+    rehash(id, watch, baseline)
+  }
+
+  const pollWatches = (): void => {
+    for (const [id, watch] of watched) {
+      let current: { mtimeMs: number; size: number }
+      try {
+        current = statSync(watch.path)
+      } catch (error) {
+        watch.dirty = true
+        if ((error as NodeJS.ErrnoException).code !== 'ENOENT') ctx.logger.warn(error)
+        continue
+      }
+      if (!watch.dirty && current.mtimeMs === watch.mtimeMs && current.size === watch.size) continue
+      // Stat-before-hash preserves a detectable older baseline for writes that
+      // land during hashing. Repeated stat changes heal a torn read.
+      rehash(id, watch, current)
+    }
+  }
+
+  // Diff the watch set against the current graph: drop watches for removed
+  // rows (or rows whose bundle path moved), add watches for new rows.
+  const syncWatches = (): void => {
+    const rows = new Map<string, string>()
+    for (const row of ctx.clientModuleHost.graph().entries) {
+      const path = ctx.clientModuleHost.clientPath(row.id)
+      if (path !== undefined) rows.set(row.id, path)
+    }
+    for (const [id, watch] of watched) {
+      if (rows.get(id) === watch.path) continue
+      watched.delete(id)
+    }
+    for (const [id, path] of rows) {
+      if (!watched.has(id)) watchRow(id, path)
+    }
+  }
+
+  ctx.effect(() => {
+    // Initial sync covers rows already in the graph; the subscription covers
+    // rows arriving later (boot-window activations, including this plugin's
+    // own row — no self-exemption, a modules/hmr rebuild rides the same chain).
+    syncWatches()
+    const unsubscribe = ctx.clientModuleHost.onGraphChanged(syncWatches)
+    const timer = setInterval(pollWatches, pollIntervalMs)
+    timer.unref()
+    return () => {
+      unsubscribe()
+      clearInterval(timer)
+      watched.clear()
+    }
+  }, 'client-hmr: bundle watches')
+
+  // --- /plugins/events SSE channel ----------------------------------------
+  const connections = new Set<ServerResponse>()
+
+  const connect = (res: ServerResponse): void => {
+    res.writeHead(200, {
+      'content-type': 'text/event-stream',
+      'cache-control': 'no-cache',
+      'connection': 'keep-alive',
+    })
+    // Comment line on open so clients/proxies see a live channel even when
+    // no rebuild ever happens; EventSource frame parsing skips it naturally.
+    res.write(': connected\n\n')
+    res.write(sseData({ type: 'graph', graph: ctx.clientModuleHost.graph() }))
+    connections.add(res)
+    res.on('close', () => { connections.delete(res) })
+  }
+
+  ctx.effect(() => {
+    const disposeRoute = ctx.httpServer.register({
+      kind: 'exact',
+      path: EVENTS_ENDPOINT,
+      handler: (req, res) => {
+        // Named routes match ahead of the carrier's method gate; keep the old
+        // global 405 semantics for non-GET hits on this endpoint.
+        if (req.method !== 'GET' && req.method !== 'HEAD') {
+          res.writeHead(405)
+          res.end()
+          return
+        }
+        connect(res)
+      },
+    })
+    const unsubscribe = ctx.clientModuleHost.onRebuilt((id, rev) => {
+      const line = sseData({ type: 'rebuilt', id, rev })
+      for (const res of connections) res.write(line)
+    })
+    return () => {
+      unsubscribe()
+      disposeRoute()
+      for (const res of connections) res.destroy()
+      connections.clear()
+    }
+  }, 'client-hmr: /plugins/events channel')
+}

packages/client/hmr/src/invariant.ts

@@ -0,0 +1,59 @@
+/**
+ * Package-owned invariant companion for `@deepseek-ai/dsh-client-hmr`.
+ * @module @deepseek-ai/dsh-client-hmr/invariant
+ */
+
+import type { Context, Fiber } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-client-hmr'
+
+/** Cordis companion plugin name. */
+export const name = 'client-hmr-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/** Live fs.watchFile pollers (this package is the composition's only stat-poll user). */
+function statWatchers(): number {
+  return process.getActiveResourcesInfo().filter(kind => kind === 'StatWatcher').length
+}
+
+/**
+ * Owned relation: every bundle stat watcher the node half starts must die
+ * with its fiber — a surviving poller would keep re-hashing bundles for a
+ * torn-down dev chain forever. Checked as a baseline delta: the StatWatcher
+ * count observed at fiber creation must be restored once disposal has drained
+ * the fiber's effects (`internal/plugin` fires at dispose start; the microtask
+ * hop lets the disposer queue its unload before `fiber.await()` joins it).
+ * SSE-connection and listener teardown live inside the same ctx.effect
+ * disposers, so the watcher count is the relation's observable proxy.
+ */
+const install: InvariantInstaller = (ctx, fail) => {
+  const baselines = new WeakMap<Fiber, number>()
+  // Async listener by design: emitPluginDisposed awaits-and-logs returned
+  // promises, so a violation surfaces loudly instead of unhandled.
+  // eslint-disable-next-line @typescript-eslint/no-misused-promises
+  ctx.on('internal/plugin', async (fiber) => {
+    if (fiber.name !== 'client-hmr') return
+    if (fiber.uid !== null) {
+      baselines.set(fiber, statWatchers())
+      return
+    }
+    const baseline = baselines.get(fiber)
+    if (baseline === undefined) return
+    await Promise.resolve()
+    await fiber.await()
+    const remaining = statWatchers()
+    if (remaining > baseline) {
+      fail(`client-hmr fiber disposed but ${remaining - baseline} bundle stat watcher(s) survived teardown`)
+    }
+  }, { global: true })
+}
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))

packages/client/hmr/tests/node-half.spec.ts

@@ -0,0 +1,204 @@
+/**
+ * Node half of the HMR plugin: bundle watches follow the graph, stat changes
+ * report through clientModuleHost.rebuilt, and everything dies with the fiber.
+ */
+import { mkdtempSync, rmSync, statSync, unlinkSync, utimesSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { Context } from 'cordis'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import type { WebBootGraph, ClientModuleHostService } from '@deepseek-ai/dsh-client-modules'
+import type { WebRoute, HttpServerService } from '@deepseek-ai/dsh-host-webserver'
+import { apply, Config, EVENTS_ENDPOINT, inject } from '../src/index.ts'
+
+const POLL_MS = 20
+
+let dir: string
+
+beforeEach(() => { dir = mkdtempSync(join(tmpdir(), 'dsh-hmr-')) })
+afterEach(() => { rmSync(dir, { recursive: true, force: true }) })
+
+/**
+ * Controllable clientModuleHost fake over a mutable id → bundle-path table.
+ * Structural (Pick+cast): the plugin only touches the read/notify surface;
+ * the service class carries private scan state a literal need not reproduce.
+ */
+type FakeHost = ClientModuleHostService & { rebuiltCalls: string[]; fireGraphChanged(): void }
+interface FakeHostOptions {
+  beforeGraphRead?: () => void
+  rebuilt?: (id: string) => string | undefined
+}
+
+function fakeClientModuleHost(rows: Map<string, string>, options: FakeHostOptions = {}): FakeHost {
+  const graphListeners = new Set<() => void>()
+  const rebuiltCalls: string[] = []
+  const fake: Pick<FakeHost, 'graph' | 'clientPath' | 'rebuilt' | 'onRebuilt' | 'onGraphChanged' | 'rebuiltCalls' | 'fireGraphChanged'> = {
+    rebuiltCalls,
+    fireGraphChanged: () => { for (const l of graphListeners) l() },
+    graph: (): WebBootGraph => {
+      options.beforeGraphRead?.()
+      return {
+        rev: 'r',
+        entries: [...rows.keys()].map(id => ({ id, url: `/plugins/${id}/client.js?rev=r`, rev: 'r' })),
+      }
+    },
+    clientPath: id => rows.get(id),
+    rebuilt: (id) => {
+      rebuiltCalls.push(id)
+      return options.rebuilt?.(id) ?? 'r2'
+    },
+    onRebuilt: () => () => {},
+    onGraphChanged: (listener) => {
+      graphListeners.add(listener)
+      return () => { graphListeners.delete(listener) }
+    },
+  }
+  return fake as FakeHost
+}
+
+// Structural fake: the plugin only touches register(); the service class
+// carries private state a literal cannot (and need not) reproduce.
+function fakeHttpServer(routes: WebRoute[]): HttpServerService {
+  const fake: Pick<HttpServerService, 'register' | 'tapIndex' | 'port'> = {
+    register(route) {
+      routes.push(route)
+      return () => { routes.splice(routes.indexOf(route), 1) }
+    },
+    tapIndex: () => () => {},
+    port: 0,
+  }
+  return fake as HttpServerService
+}
+
+async function mount(clientModuleHost: FakeHost, httpServer: HttpServerService) {
+  const ctx = new Context()
+  ctx.provide('clientModuleHost', clientModuleHost)
+  ctx.provide('httpServer', httpServer)
+  const fiber = ctx.plugin(
+    { inject: [...inject], Config, apply },
+    { pollIntervalMs: POLL_MS },
+  )
+  await fiber.await()
+  return fiber
+}
+
+describe('hmr node half', () => {
+  it('watches graph bundles, reports stat changes, and unwatches on dispose', async () => {
+    const bundle = join(dir, 'a.js')
+    writeFileSync(bundle, 'v1')
+    const clientModuleHost = fakeClientModuleHost(new Map([['pkg-a', bundle]]))
+    const routes: WebRoute[] = []
+    const fiber = await mount(clientModuleHost, fakeHttpServer(routes))
+
+    expect(routes).toHaveLength(1)
+    expect(routes[0]).toMatchObject({ kind: 'exact', path: EVENTS_ENDPOINT })
+    expect(clientModuleHost.rebuiltCalls).toEqual(['pkg-a'])
+    clientModuleHost.rebuiltCalls.length = 0
+
+    // Nudge mtime past stat granularity so the poller sees a content signal.
+    await new Promise(resolve => setTimeout(resolve, POLL_MS * 2))
+    writeFileSync(bundle, 'v2-longer')
+    await vi.waitFor(() => { expect(clientModuleHost.rebuiltCalls).toContain('pkg-a') }, { timeout: 3_000 })
+
+    await fiber.dispose()
+    expect(routes).toHaveLength(0)
+    // Watcher gone: further file changes report nothing.
+    clientModuleHost.rebuiltCalls.length = 0
+    writeFileSync(bundle, 'v3-even-longer')
+    await new Promise(resolve => setTimeout(resolve, POLL_MS * 4))
+    expect(clientModuleHost.rebuiltCalls).toHaveLength(0)
+  })
+
+  it('follows graph changes: rows added after activation get watched', async () => {
+    const early = join(dir, 'early.js')
+    const late = join(dir, 'late.js')
+    writeFileSync(early, 'v1')
+    const rows = new Map([['pkg-early', early]])
+    const clientModuleHost = fakeClientModuleHost(rows)
+    const fiber = await mount(clientModuleHost, fakeHttpServer([]))
+    clientModuleHost.rebuiltCalls.length = 0
+
+    writeFileSync(late, 'v1')
+    rows.set('pkg-late', late)
+    clientModuleHost.fireGraphChanged()
+    expect(clientModuleHost.rebuiltCalls).toEqual(['pkg-late'])
+    clientModuleHost.rebuiltCalls.length = 0
+
+    await new Promise(resolve => setTimeout(resolve, POLL_MS * 2))
+    writeFileSync(late, 'v2-longer')
+    await vi.waitFor(() => { expect(clientModuleHost.rebuiltCalls).toContain('pkg-late') }, { timeout: 3_000 })
+
+    rows.delete('pkg-late')
+    clientModuleHost.fireGraphChanged()
+    clientModuleHost.rebuiltCalls.length = 0
+    writeFileSync(late, 'v3-even-longer')
+    await new Promise(resolve => setTimeout(resolve, POLL_MS * 3))
+    expect(clientModuleHost.rebuiltCalls).toHaveLength(0)
+    await fiber.dispose()
+  })
+
+  it('rehashes after baseline capture so a construction-window write cannot become the baseline', async () => {
+    const bundle = join(dir, 'construction.js')
+    writeFileSync(bundle, 'v1')
+    let rewrite = true
+    const clientModuleHost = fakeClientModuleHost(new Map([['pkg-a', bundle]]), {
+      beforeGraphRead: () => {
+        if (!rewrite) return
+        rewrite = false
+        // The graph carries the hash from before this write. The old
+        // fs.watchFile registration asynchronously captured the new file as
+        // its first baseline and never requested a re-hash.
+        writeFileSync(bundle, 'v2-written-during-watch-construction')
+      },
+    })
+
+    const fiber = await mount(clientModuleHost, fakeHttpServer([]))
+
+    expect(clientModuleHost.rebuiltCalls).toEqual(['pkg-a'])
+    clientModuleHost.rebuiltCalls.length = 0
+    await new Promise(resolve => setTimeout(resolve, POLL_MS * 3))
+    expect(clientModuleHost.rebuiltCalls).toHaveLength(0)
+    await fiber.dispose()
+  })
+
+  it('marks a vanished bundle dirty so identical metadata still re-hashes after it reappears', async () => {
+    const bundle = join(dir, 'replace.js')
+    writeFileSync(bundle, 'seed')
+    const fixedTime = new Date(1_600_000_000_000)
+    utimesSync(bundle, fixedTime, fixedTime)
+    const baseline = statSync(bundle)
+    const clientModuleHost = fakeClientModuleHost(new Map([['pkg-a', bundle]]))
+    const fiber = await mount(clientModuleHost, fakeHttpServer([]))
+    clientModuleHost.rebuiltCalls.length = 0
+
+    unlinkSync(bundle)
+    await new Promise(resolve => setTimeout(resolve, POLL_MS * 2))
+    writeFileSync(bundle, 'x'.repeat(baseline.size))
+    utimesSync(bundle, fixedTime, fixedTime)
+    const restored = statSync(bundle)
+    expect({ mtimeMs: restored.mtimeMs, size: restored.size }).toEqual({
+      mtimeMs: baseline.mtimeMs,
+      size: baseline.size,
+    })
+    await vi.waitFor(() => { expect(clientModuleHost.rebuiltCalls).toEqual(['pkg-a']) }, { timeout: 3_000 })
+    await fiber.dispose()
+  })
+
+  it('retains a dirty baseline when the immediate re-hash races a rename', async () => {
+    const bundle = join(dir, 'rename.js')
+    writeFileSync(bundle, 'v1')
+    let first = true
+    const clientModuleHost = fakeClientModuleHost(new Map([['pkg-a', bundle]]), {
+      rebuilt: () => {
+        if (!first) return 'r2'
+        first = false
+        throw Object.assign(new Error('bundle renamed'), { code: 'ENOENT' })
+      },
+    })
+
+    const fiber = await mount(clientModuleHost, fakeHttpServer([]))
+
+    await vi.waitFor(() => { expect(clientModuleHost.rebuiltCalls).toEqual(['pkg-a', 'pkg-a']) }, { timeout: 3_000 })
+    await fiber.dispose()
+  })
+})

packages/client/hmr/tsconfig.json

@@ -8,7 +8,7 @@
       "DOM",
       "DOM.Iterable"
     ],
-    "types": []
+    "types": ["node"]
   },
   "include": [
     "src"
@@ -18,7 +18,16 @@
       "path": "../../../vendor/cordis"
     },
     {
-      "path": "../web-react"
+      "path": "../../../vendor/loader"
+    },
+    {
+      "path": "../modules"
+    },
+    {
+      "path": "../../host/webserver"
+    },
+    {
+      "path": "../../../vendor/schemastery"
     },
     {
       "path": "../../support/invariants"

packages/client/hmr/tsdown.config.ts

@@ -0,0 +1,3 @@
+import { clientBundle } from '../tsdown.client.ts'
+
+export default clientBundle('@deepseek-ai/dsh-client-hmr', ['lib/types/index.js', 'lib/types/invariant.js'])

packages/client/i18n/README.md

@@ -1,16 +0,0 @@
-# @deepseek-ai/dsh-client-i18n
-
-i18n plugin: I18nService (ns×locale dictionaries, bind(ns)→t with a stable function identity, locale store). Contract: api-contracts v3 §8.
-
-## Model Experience
-
-None, as the i18n registry serves browser UI copy; nothing here reaches a model request.
-
-#### KV Cache effect
-
-None; this package neither assembles nor sends a provider request.
-
-## Known Limitations and Deferred Work
-
-- **zh/en ship as empty structures** — the existing UI copy is inline Chinese; extraction into dictionaries is deferred repo-wide work, so `bind(ns)` consumers today mostly receive key-echo fallbacks.
-- **Locale switching re-renders the whole tree** — accepted as a low-frequency operation; no per-namespace subscription granularity.

packages/client/i18n/src/client/index.ts

@@ -1,108 +0,0 @@
-/**
- * i18n plugin, browser half: namespace x locale dictionary registry with a
- * bound translate function whose reference is stable (safe for inject
- * surfaces). Mounts ctx.i18n and seeds the zh/en base dictionaries.
- * Contract: api-contracts v3 section 8.
- */
-import type { Context } from 'cordis'
-import type { SnapshotStore } from '@deepseek-ai/dsh-client-web-react'
-import { createSnapshotStore } from '@deepseek-ai/dsh-client-web-react'
-import { en } from '../locales/en.ts'
-import { zh } from '../locales/zh.ts'
-
-/** Translate a key with optional params. */
-export type Translate = (key: string, params?: Record<string, unknown>) => string
-
-/** Locale dictionary: flat key to template string ({name} placeholders). */
-export type LocaleDict = Record<string, string>
-
-declare module 'cordis' {
-  interface Context {
-    i18n: I18nService
-  }
-}
-
-/** Fallback locale consulted after the active locale misses. */
-export const FALLBACK_LOCALE = 'zh'
-
-/** Shared namespace for shell-level texts. */
-export const COMMON_NS = 'common'
-
-/**
- * Dictionary registry plus locale switch. Lookup chain per key: active locale
- * -> zh fallback -> the key itself (missing text stays visible, fail loud in
- * the UI rather than blank).
- */
-export class I18nService {
-  private dicts = new Map<string, Map<string, LocaleDict>>()
-  private bound = new Map<string, Translate>()
-  private localeStore = createSnapshotStore<string>(FALLBACK_LOCALE)
-
-  /**
-   * Register a dictionary for a namespace and locale. Duplicate (ns, locale)
-   * throws (single occupant; a namespace's texts have one owner).
-   * @param ns - namespace.
-   * @param locale - locale tag (zh/en to start).
-   * @param dict - dictionary.
-   * @returns disposer (idempotent).
-   */
-  register(ns: string, locale: string, dict: LocaleDict): () => void {
-    let locales = this.dicts.get(ns)
-    if (!locales) {
-      locales = new Map()
-      this.dicts.set(ns, locales)
-    }
-    if (locales.has(locale)) throw new Error(`i18n namespace "${ns}" already has locale "${locale}"`)
-    locales.set(locale, dict)
-    return () => {
-      const owner = this.dicts.get(ns)
-      if (owner?.get(locale) === dict) owner.delete(locale)
-    }
-  }
-
-  /**
-   * Bind a namespace to a translate function. The returned reference is
-   * stable per namespace (repeat binds return the same function), so it can
-   * ride inject surfaces without breaking memoization.
-   * @param ns - namespace.
-   * @returns the translate function (reads the locale store at call time).
-   */
-  bind(ns: string): Translate {
-    let t = this.bound.get(ns)
-    if (!t) {
-      t = (key, params) => this.translate(ns, key, params)
-      this.bound.set(ns, t)
-      return t
-    }
-    return t
-  }
-
-  /** Active locale store (switching re-renders the tree; low frequency). */
-  get locale(): SnapshotStore<string> {
-    return this.localeStore
-  }
-
-  private translate(ns: string, key: string, params?: Record<string, unknown>): string {
-    const locales = this.dicts.get(ns)
-    const template = locales?.get(this.localeStore.getSnapshot())?.[key]
-      ?? locales?.get(FALLBACK_LOCALE)?.[key]
-      ?? key
-    if (!params) return template
-    return template.replace(/\{(\w+)\}/g, (match, name: string) =>
-      name in params ? String(params[name]) : match)
-  }
-}
-
-/** Required services (none; the loader passes the export surface as an object plugin). */
-export const inject: string[] = []
-
-/**
- * Client plugin body: provide the i18n service with base dictionaries.
- * @param ctx - client cordis context.
- */
-export function apply(ctx: Context): void {
-  const i18n = new I18nService()
-  i18n.register(COMMON_NS, 'zh', zh)
-  i18n.register(COMMON_NS, 'en', en)
-  ctx.provide('i18n', i18n)
-}

packages/client/i18n/src/index.ts

@@ -1,11 +0,0 @@
-/**
- * i18n plugin, node half. Pure UI plugin: the empty apply exists so the
- * plugin appears in the host cordis.yml / Loader (load and lifecycle follow
- * the host; the browser half ships via exports["./client"], discovered
- * through the package.json dshClient declaration). Everything else —
- * I18nService, Translate, LocaleDict — lives in the client half; consumers
- * import the /client subpath. Contract: api-contracts v3 section 8.
- */
-
-/** Host plugin body — no host-side behavior for the i18n plugin. */
-export function apply(): void {}

packages/client/i18n/tests/i18n.spec.ts

@@ -1,53 +0,0 @@
-import { describe, expect, it } from 'vitest'
-import { I18nService } from '@deepseek-ai/dsh-client-i18n/client'
-
-describe('I18nService', () => {
-  it('translates from the active locale with zh fallback then key passthrough', () => {
-    const i18n = new I18nService()
-    i18n.register('ns', 'zh', { hello: '你好', onlyZh: '仅中文' })
-    i18n.register('ns', 'en', { hello: 'Hello' })
-    const t = i18n.bind('ns')
-    expect(i18n.locale.getSnapshot()).toBe('zh')
-    expect(t('hello')).toBe('你好')
-    i18n.locale.set('en')
-    expect(t('hello')).toBe('Hello')
-    expect(t('onlyZh')).toBe('仅中文')
-    expect(t('missing.key')).toBe('missing.key')
-  })
-
-  it('interpolates {name} params and leaves unknown placeholders intact', () => {
-    const i18n = new I18nService()
-    i18n.register('ns', 'zh', { greet: '你好，{name}！第 {n} 次', partial: '{known} 与 {unknown}' })
-    const t = i18n.bind('ns')
-    expect(t('greet', { name: '世界', n: 2 })).toBe('你好，世界！第 2 次')
-    expect(t('partial', { known: 'A' })).toBe('A 与 {unknown}')
-    expect(t('greet')).toBe('你好，{name}！第 {n} 次')
-  })
-
-  it('bind returns a stable reference per namespace', () => {
-    const i18n = new I18nService()
-    expect(i18n.bind('a')).toBe(i18n.bind('a'))
-    expect(i18n.bind('a')).not.toBe(i18n.bind('b'))
-  })
-
-  it('duplicate (ns, locale) throws; disposer unregisters and is idempotent', () => {
-    const i18n = new I18nService()
-    const dispose = i18n.register('ns', 'zh', { k: 'v1' })
-    expect(() => i18n.register('ns', 'zh', { k: 'v2' })).toThrow('already has locale')
-    dispose()
-    dispose()
-    const t = i18n.bind('ns')
-    expect(t('k')).toBe('k')
-    i18n.register('ns', 'zh', { k: 'v2' })
-    expect(t('k')).toBe('v2')
-  })
-
-  it('locale store is subscribable (snapshot store contract)', () => {
-    const i18n = new I18nService()
-    let notified = 0
-    i18n.locale.subscribe(() => { notified += 1 })
-    i18n.locale.set('en')
-    expect(i18n.locale.getSnapshot()).toBe('en')
-    expect(notified).toBe(1)
-  })
-})

packages/client/i18n/tests/invariant.spec.ts

@@ -1,30 +0,0 @@
-import { describe, expect, it } from 'vitest'
-import { Context } from 'cordis'
-import { apply as nodeApply } from '@deepseek-ai/dsh-client-i18n'
-import { apply as clientApply, COMMON_NS, I18nService, inject } from '@deepseek-ai/dsh-client-i18n/client'
-import * as I18nInvariant from '@deepseek-ai/dsh-client-i18n/invariant'
-import InvariantService from '@deepseek-ai/dsh-invariants'
-
-describe('invariant companion', () => {
-  it('registers under the package name with an empty installer', async () => {
-    const ctx = new Context()
-    await ctx.plugin(InvariantService, { enabled: true })
-    await expect(ctx.plugin(I18nInvariant).await()).resolves.toBeDefined()
-  })
-
-  it('node-half apply is a no-op host placeholder', () => {
-    nodeApply()
-    expect(true).toBe(true) // reaching here without throw is the contract
-  })
-
-  it('client apply provides ctx.i18n seeded with the zh/en common namespace', async () => {
-    expect(inject).toEqual([])
-    const ctx = new Context()
-    await ctx.plugin({ inject, apply: clientApply }).await()
-    const i18n = ctx.get('i18n')
-    expect(i18n).toBeInstanceOf(I18nService)
-    // Seeded dictionaries occupy the (ns, locale) seats even while empty.
-    expect(() => (i18n as I18nService).register(COMMON_NS, 'zh', {})).toThrow('already has locale')
-    expect(() => (i18n as I18nService).register(COMMON_NS, 'en', {})).toThrow('already has locale')
-  })
-})

packages/client/i18n/tsdown.config.ts

@@ -1,3 +0,0 @@
-import { clientBundle } from '../tsdown.client.ts'
-
-export default clientBundle('@deepseek-ai/dsh-client-i18n', ['lib/types/index.js', 'lib/types/invariant.js'])

packages/client/locale/README.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+README.md: 9015af2b44a33771b06863ace139fe97695df616
+README.zh.md: 6b129bcabbef5b5a00c5073ebc9142a0e406ddba

packages/client/locale/README.md

@@ -0,0 +1,18 @@
+# @deepseek-ai/dsh-client-locale
+
+English | [中文](README.zh.md)
+
+Locale plugin: LocaleService — the browser locale preference (`zh`/`en`, persisted under `dsh.locale`, getter/setter with `locale/change` snapshots) plus the ns×locale dictionary registry (`bind(ns)`→t with a stable function identity; lookup chain active → zh → key).
+
+## Model Experience
+
+None, as the locale registry serves browser UI copy; nothing here reaches a model request.
+
+#### KV Cache effect
+
+None; this package neither assembles nor sends a provider request.
+
+## Known Limitations and Deferred Work
+
+- **Only the Settings surface is translated** — other pages keep inline copy; repo-wide extraction into dictionaries is deferred.
+- **Locale switching re-renders subscribed consumers only** — sections not wired to `locale/change` keep their rendered text until remount.

packages/client/locale/README.zh.md

@@ -0,0 +1,18 @@
+# @deepseek-ai/dsh-client-locale
+
+[English](README.md) | 中文
+
+locale 插件：LocaleService 包含浏览器 locale 偏好（`zh`／`en`，以 `dsh.locale` 为键持久化；提供 getter／setter，并生成 `locale/change` 快照），以及 ns×locale 字典注册表（`bind(ns)`→t 的函数标识稳定；查找链为 active → zh → key）。
+
+## 模型体验
+
+无。locale 注册表为浏览器 UI 文案提供服务；这里没有任何内容进入模型请求。
+
+#### KV Cache 影响
+
+无；该包既不组装也不发送提供方请求。
+
+## 已知限制与暂缓事项
+
+- **只有设置界面完成翻译**：其他页面仍保留内联文案；将全仓文案提取到字典的工作暂缓。
+- **切换 locale 只重新渲染已订阅的消费方**：未接入 `locale/change` 的分区会保留已渲染文本，直到重新挂载。

packages/client/locale/package.json

@@ -0,0 +1,62 @@
+{
+  "name": "@deepseek-ai/dsh-client-locale",
+  "description": "Locale plugin: LocaleService (zh/en preference with getter/setter/change event + persistence; ns x locale dictionaries, bind(ns) -> t); registers the Language settings row",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./client": {
+      "types": "./lib/types/client/index.d.ts",
+      "default": "./lib/client.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "dshClient": {
+    "inject": [
+      "@deepseek-ai/dsh-client-runtime"
+    ],
+    "platform": "web",
+    "immediately": true
+  },
+  "license": "BSD-3-Clause",
+  "peerDependencies": {
+    "@deepseek-ai/dsh-client-runtime": "^0.0.1",
+    "@deepseek-ai/dsh-client-ui-primitives": "^0.0.1",
+    "@deepseek-ai/dsh-client-ui-slots": "^0.0.1",
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "cordis": "^4.0.0-rc.7",
+    "react": "^18.2.0"
+  },
+  "devDependencies": {
+    "@deepseek-ai/dsh-client-runtime": "workspace:^",
+    "@deepseek-ai/dsh-client-ui-primitives": "workspace:^",
+    "@deepseek-ai/dsh-client-ui-slots": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@types/react": "~18.3.1",
+    "cordis": "^4.0.0-rc.7",
+    "react": "^18.2.0"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/client.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "scripts": {
+    "bundle": "tsdown",
+    "watch": "tsdown --watch"
+  }
+}

packages/client/locale/src/client/LanguageRow.module.css

@@ -0,0 +1,51 @@
+/* Language row (figma 'Setting-Cell': gap 8, pad 16/0, hairline separator;
+ * the section column removes the separator on its last child). */
+
+.row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  padding: 16px 0;
+  border-bottom: 1px solid var(--dsw-alias-border-l2);
+}
+
+.rowText {
+  flex: 1;
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  padding-right: 48px;
+}
+
+.title {
+  font-size: 14px;
+  font-weight: 400;
+  line-height: 22px;
+  color: var(--dsw-alias-label-primary);
+}
+
+/* Selector pill (figma 'Selector': h36 r18, fill #F5F6F7, pad 0/14, gap 12). */
+.selector {
+  display: inline-flex;
+  align-items: center;
+  gap: 12px;
+  height: 36px;
+  padding: 0 14px;
+  border: none;
+  border-radius: 18px;
+  background: var(--dsw-alias-bg-module-platform);
+  font: inherit;
+  font-size: 14px;
+  line-height: 22px;
+  color: var(--dsw-alias-label-primary);
+  cursor: pointer;
+}
+
+.selector:hover {
+  background: var(--dsw-alias-interactive-bg-hover);
+}
+
+.chevron {
+  flex: none;
+}

packages/client/locale/src/client/LanguageRow.tsx

@@ -0,0 +1,68 @@
+/**
+ * Language preference row registered into the General section item slot
+ * (figma 501:30011 'Setting-Cell'): title + selector pill opening the locale
+ * menu. Registered by this package — the locale feature owns its own
+ * settings surface.
+ */
+import { useState } from 'react'
+import type { PropsRuntime, PropsStore } from '@deepseek-ai/dsh-client-ui-slots'
+import { IconChevronDownOutline14, Menu } from '@deepseek-ai/dsh-client-ui-primitives'
+import type {} from './settings-contract.ts'
+import type { createLanguageRowStore } from './settings-store.ts'
+import css from './LanguageRow.module.css'
+
+/** Injected business face: namespace-bound translate + the preference write. */
+export interface LanguageRowInjected {
+  /** Translate a `settings.locale` dictionary key to the active-locale text. */
+  t: (key: string) => string
+  /** Switch the active locale (a registered locale id). */
+  setLocale: (id: string) => void
+}
+
+/** Full component props: runtime share + store share + injected face. */
+export type LanguageRowComponentProps =
+  PropsRuntime<'settings.general.item'> & PropsStore<ReturnType<typeof createLanguageRowStore>> & LanguageRowInjected
+
+/**
+ * Render the Language row.
+ * @param props - composed slot props.
+ * @returns the row element tree.
+ */
+export function LanguageRow({ t, setLocale, useStore }: LanguageRowComponentProps) {
+  const active = useStore(s => s.active)
+  const options = useStore(s => s.options)
+  const [open, setOpen] = useState(false)
+  const activeLabel = options.find(o => o.id === active)?.label ?? active
+
+  return (
+    <div className={css.row}>
+      <div className={css.rowText}>
+        <div className={css.title}>{t('language.title')}</div>
+      </div>
+      <Menu
+        open={open}
+        onClose={() => { setOpen(false) }}
+        items={options.map(o => ({ id: o.id, label: o.label }))}
+        selectedId={active}
+        onSelect={(id) => {
+          setLocale(id)
+          setOpen(false)
+        }}
+        align="end"
+        portal
+        anchor={(
+          <button
+            type="button"
+            className={css.selector}
+            aria-haspopup="menu"
+            aria-expanded={open}
+            onClick={() => { setOpen(v => !v) }}
+          >
+            {activeLabel}
+            <IconChevronDownOutline14 className={css.chevron} />
+          </button>
+        )}
+      />
+    </div>
+  )
+}

packages/client/locale/src/client/index.ts

@@ -0,0 +1,248 @@
+/**
+ * Browser-side locale registry. Bound translation functions retain stable
+ * identity for injected consumers. The plugin also registers the Language
+ * preference row into the settings General section — the locale feature owns
+ * its own settings surface.
+ */
+import type { Context } from 'cordis'
+import { deferRegistration, type BoundActions } from '@deepseek-ai/dsh-client-ui-slots'
+import type { ClientContext } from '@deepseek-ai/dsh-client-runtime/client'
+import { en } from '../locales/en.ts'
+import { zh } from '../locales/zh.ts'
+import type { LanguageRowInjected } from './LanguageRow.tsx'
+import { LanguageRow } from './LanguageRow.tsx'
+import { createLanguageRowStore } from './settings-store.ts'
+
+export type { LanguageRowComponentProps, LanguageRowInjected } from './LanguageRow.tsx'
+export type { LanguageOptionRow, LanguageRowState } from './settings-store.ts'
+export type { SettingsGeneralItemOwnerProps } from './settings-contract.ts'
+
+/** Translate a key with optional params. */
+export type Translate = (key: string, params?: Record<string, unknown>) => string
+
+/** Locale dictionary: flat key to template string ({name} placeholders). */
+export type LocaleDict = Record<string, string>
+
+/** Locale identifier: the two shipped locales. */
+export type LocaleId = 'zh' | 'en'
+
+/** One selectable locale: id plus its self-described display name. */
+export interface LocaleDefinition {
+  /** Locale id (persisted; the setLocale argument). */
+  id: LocaleId
+  /** Display name in its own language (中文 / English). */
+  label: string
+}
+
+/** Immutable locale state published on every change. */
+export interface LocaleSnapshot {
+  /** Active locale id. */
+  active: LocaleId
+  /** Selectable locales in display order. */
+  locales: readonly LocaleDefinition[]
+  /** Monotonic change counter (registry or active changes). */
+  revision: number
+}
+
+declare module 'cordis' {
+  interface Context {
+    locale: LocaleService
+  }
+  interface Events {
+    /**
+     * Locale state changed (active locale switched or registry updated).
+     * @param snapshot - Current immutable locale snapshot.
+     * @mode emit
+     */
+    'locale/change'(snapshot: LocaleSnapshot): void
+  }
+}
+
+/** Fallback locale consulted after the active locale misses (also the default). */
+export const FALLBACK_LOCALE: LocaleId = 'zh'
+
+/** Shared namespace for shell-level texts. */
+export const COMMON_NS = 'common'
+
+/** Namespace owning this feature's settings-row copy. */
+export const SETTINGS_NS = 'settings.locale'
+
+/** localStorage key holding the persisted locale id. */
+export const STORAGE_KEY = 'dsh.locale'
+
+/** The two shipped locales. */
+const LOCALES: readonly LocaleDefinition[] = Object.freeze([
+  { id: 'zh', label: '中文' },
+  { id: 'en', label: 'English' },
+])
+
+/**
+ * Dictionary registry plus locale preference. Lookup chain per key: active
+ * locale -> zh fallback -> the key itself (missing text stays visible, fail
+ * loud in the UI rather than blank). Reads go through {@link getLocale};
+ * writes only through {@link setLocale}; continuous sync only through the
+ * `locale/change` event.
+ */
+export class LocaleService {
+  private dicts = new Map<string, Map<string, LocaleDict>>()
+  private bound = new Map<string, Translate>()
+  private snapshot: LocaleSnapshot
+  private readonly ctx: Context
+
+  /**
+   * @param ctx - owning context (change events are emitted on it).
+   */
+  constructor(ctx: Context) {
+    this.ctx = ctx
+    this.snapshot = Object.freeze({ active: restorePreference(), locales: LOCALES, revision: 0 })
+  }
+
+  /**
+   * Read the current immutable locale snapshot.
+   * @returns the current snapshot (stable reference until the next change).
+   */
+  getLocale(): LocaleSnapshot {
+    return this.snapshot
+  }
+
+  /**
+   * Switch the active locale — the only preference write entry. Persists the
+   * id and emits `locale/change`.
+   * @param id - a registered locale id; unknown ids throw.
+   */
+  setLocale(id: string): void {
+    const match = this.snapshot.locales.find(l => l.id === id)
+    if (match === undefined) throw new Error(`locale "${id}" is not registered`)
+    if (this.snapshot.active === match.id) return
+    this.snapshot = Object.freeze({
+      active: match.id,
+      locales: this.snapshot.locales,
+      revision: this.snapshot.revision + 1,
+    })
+    persistPreference(match.id)
+    this.ctx.emit('locale/change', this.snapshot)
+  }
+
+  /**
+   * Register a dictionary for a namespace and locale. Duplicate (ns, locale)
+   * throws (single occupant; a namespace's texts have one owner).
+   * @param ns - namespace.
+   * @param locale - locale tag (zh/en to start).
+   * @param dict - dictionary.
+   * @returns disposer (idempotent).
+   */
+  register(ns: string, locale: string, dict: LocaleDict): () => void {
+    let locales = this.dicts.get(ns)
+    if (!locales) {
+      locales = new Map()
+      this.dicts.set(ns, locales)
+    }
+    if (locales.has(locale)) throw new Error(`locale namespace "${ns}" already has locale "${locale}"`)
+    locales.set(locale, dict)
+    return () => {
+      const owner = this.dicts.get(ns)
+      if (owner?.get(locale) === dict) owner.delete(locale)
+    }
+  }
+
+  /**
+   * Bind a namespace to a translate function. The returned reference is
+   * stable per namespace (repeat binds return the same function), so it can
+   * ride inject surfaces without breaking memoization.
+   * @param ns - namespace.
+   * @returns the translate function (reads the active locale at call time).
+   */
+  bind(ns: string): Translate {
+    let t = this.bound.get(ns)
+    if (!t) {
+      t = (key, params) => this.translate(ns, key, params)
+      this.bound.set(ns, t)
+      return t
+    }
+    return t
+  }
+
+  private translate(ns: string, key: string, params?: Record<string, unknown>): string {
+    const locales = this.dicts.get(ns)
+    const template = locales?.get(this.snapshot.active)?.[key]
+      ?? locales?.get(FALLBACK_LOCALE)?.[key]
+      ?? key
+    if (!params) return template
+    return template.replace(/\{(\w+)\}/g, (match, name: string) =>
+      name in params ? String(params[name]) : match)
+  }
+}
+
+/** Read the persisted locale id; unknown or unreadable values fall back to zh. */
+function restorePreference(): LocaleId {
+  // Non-browser runs (node e2e booting the client tree) have no localStorage.
+  if (typeof localStorage === 'undefined') return FALLBACK_LOCALE
+  try {
+    const stored = localStorage.getItem(STORAGE_KEY)
+    if (stored === 'zh' || stored === 'en') return stored
+  } catch {
+    // Storage access can throw (privacy mode); the default below covers it.
+  }
+  return FALLBACK_LOCALE
+}
+
+/** Persist the locale id; storage failures are non-fatal (preference resets next boot). */
+function persistPreference(id: LocaleId): void {
+  if (typeof localStorage === 'undefined') return
+  try {
+    localStorage.setItem(STORAGE_KEY, id)
+  } catch {
+    // Storage access can throw (privacy mode / quota); the preference simply
+    // does not survive the session.
+  }
+}
+
+/** Required services: the slot registry (the feature registers its own settings row). */
+export const inject = ['slots']
+
+/**
+ * Client plugin body: provide the locale service with base dictionaries and
+ * register the feature-owned Language preference row into the General
+ * section's item slot (a feature owns its settings surface).
+ * @param ctx - client cordis context.
+ */
+export function apply(ctx: ClientContext): void {
+  const locale = new LocaleService(ctx)
+  locale.register(COMMON_NS, 'zh', zh)
+  locale.register(COMMON_NS, 'en', en)
+  locale.register(SETTINGS_NS, 'zh', { 'language.title': '语言' })
+  locale.register(SETTINGS_NS, 'en', { 'language.title': 'Language' })
+  ctx.provide('locale', locale)
+
+  const store = createLanguageRowStore()
+  let bound: BoundActions<typeof store> | undefined
+  const sync = (snapshot: LocaleSnapshot): void => {
+    bound?.sync(
+      snapshot.active,
+      snapshot.locales.map(l => ({ id: l.id, label: l.label })),
+      snapshot.revision,
+    )
+  }
+  ctx.on('locale/change', sync)
+  const injected = (actions: BoundActions<typeof store>): LanguageRowInjected => {
+    bound = actions
+    // Re-sync from the getter so no event is lost between registration and
+    // first render (the store's revision guard drops stale duplicates).
+    sync(locale.getLocale())
+    return {
+      t: locale.bind(SETTINGS_NS),
+      setLocale: (id) => { locale.setLocale(id) },
+    }
+  }
+  ctx.effect(() => {
+    const deferred = deferRegistration(ctx.slots, 'settings.general.item', LanguageRow, () =>
+      ctx.slots.register({
+        name: 'settings.general.item',
+        id: 'language',
+        order: 0,
+        store,
+        inject: injected,
+      }, LanguageRow))
+    return () => { deferred.dispose() }
+  }, 'locale: language settings row registration')
+}

packages/client/locale/src/client/settings-contract.ts

@@ -0,0 +1,26 @@
+/**
+ * The `settings.general.item` slot type — one preference row inside the
+ * settings General section, contributed by the feature plugin that owns the
+ * preference (locale → Language, ui-theme → Appearance). Options: `id` (row
+ * key), `order` (row position). Rows draw their own internals (row layout,
+ * separators via CSS); the section column only stacks them.
+ *
+ * TYPE HOME RATIONALE: the slot is declared at runtime by
+ * ui-settings-general's General entry, but its type lives here — this
+ * package is the common dependency of every item registrant (any settings
+ * row carries copy, so every registrant already depends on locale), whereas
+ * the declarer's own contract is unreachable for locale/ui-theme without a
+ * reference cycle.
+ */
+declare module '@deepseek-ai/dsh-client-ui-slots' {
+  interface SlotMap {
+    /** One preference row inside the settings General section (see module JSDoc). */
+    'settings.general.item': { kind: 'list'; scope: 'root'; owner: SettingsGeneralItemOwnerProps }
+  }
+}
+
+/** Owner share of a General preference row (the section supplies nothing). */
+export interface SettingsGeneralItemOwnerProps {
+  /** Marker field: item owner props are intentionally empty. */
+  children?: never
+}

packages/client/locale/src/client/settings-store.ts

@@ -0,0 +1,47 @@
+/**
+ * Language row slot store: a mirror of the locale service snapshot. The
+ * plugin's apply-world change listener is the only writer; the row component
+ * reads via props.useStore.
+ */
+import { defineStore, type EngineStoreHandle } from '@deepseek-ai/dsh-client-runtime/client'
+
+/** One selectable locale row (id + self-described label). */
+export interface LanguageOptionRow {
+  /** Locale id (the setLocale argument). */
+  id: string
+  /** Display name in its own language (中文 / English). */
+  label: string
+}
+
+/** Store state mirrored from the locale snapshot. */
+export interface LanguageRowState {
+  /** Active locale id. */
+  active: string
+  /** Selectable locales in display order. */
+  options: LanguageOptionRow[]
+  /** Service revision; -1 until first sync so revision 0 lands as a change. */
+  revision: number
+}
+
+/** Declared action shape giving the exported factory a stable return type. */
+type LanguageRowActions = {
+  sync: (draft: LanguageRowState, active: string, options: LanguageOptionRow[], revision: number) => void
+}
+
+/**
+ * Declares the Language row state and write surface.
+ * @returns the store handle.
+ */
+export function createLanguageRowStore(): EngineStoreHandle<LanguageRowState, LanguageRowActions> {
+  return defineStore({
+    init: (): LanguageRowState => ({ active: '', options: [], revision: -1 }),
+    actions: {
+      sync: (d, active: string, options: LanguageOptionRow[], revision: number) => {
+        if (revision <= d.revision) return
+        d.active = active
+        d.options = options
+        d.revision = revision
+      },
+    },
+  })
+}

packages/client/locale/src/css-modules.d.ts

@@ -0,0 +1,6 @@
+declare module '*.module.css' {
+  const classes: Record<string, string>
+  export default classes
+}
+
+declare module '*.css'

packages/client/locale/src/index.ts

@@ -0,0 +1,4 @@
+/** Host loader entry for the browser implementation exported from `./client`. */
+
+/** Host plugin body — no host-side behavior for the locale plugin. */
+export function apply(): void {}

packages/client/locale/src/invariant.ts

@@ -1,16 +1,16 @@
 /**
- * Package-owned invariant companion for `@deepseek-ai/dsh-client-i18n`.
- * @module @deepseek-ai/dsh-client-i18n/invariant
+ * Package-owned invariant companion for `@deepseek-ai/dsh-client-locale`.
+ * @module @deepseek-ai/dsh-client-locale/invariant
  */
 
 /* jscpd:ignore-start */
 import type { Context } from 'cordis'
 import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
 
-const PACKAGE_NAME = '@deepseek-ai/dsh-client-i18n'
+const PACKAGE_NAME = '@deepseek-ai/dsh-client-locale'
 
 /** Cordis companion plugin name. */
-export const name = 'client-i18n-invariant'
+export const name = 'client-locale-invariant'
 /** Service required before the companion can reserve package ownership. */
 export const inject = ['invariants']
 

packages/client/locale/tests/apply.spec.ts

@@ -0,0 +1,116 @@
+/** locale apply wiring: service + dictionaries provision, declaration-aware
+ * Language row registration, snapshot projection into the row store, and
+ * recovery after an HMR collapse of the declaring entry. */
+import { Context } from 'cordis'
+import { describe, expect, it } from 'vitest'
+import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
+import { apply, inject, SETTINGS_NS } from '@deepseek-ai/dsh-client-locale/client'
+import type { LanguageRowInjected, LocaleService } from '@deepseek-ai/dsh-client-locale/client'
+import { LanguageRow } from '../src/client/LanguageRow.tsx'
+import type { createLanguageRowStore } from '../src/client/settings-store.ts'
+
+const SLOT = 'settings.general.item'
+
+async function bench() {
+  const ctx = new Context()
+  await ctx.plugin(SlotsService).await()
+  return { ctx, slots: ctx.get('slots') as SlotsService }
+}
+
+/** Stand in for the settings shell: declare the General item slot from root. */
+function declareItems(slots: SlotsService): () => void {
+  return slots.register(
+    { name: 'root', children: { [SLOT]: { kind: 'list', scope: 'root' } } } as never,
+    () => null,
+  )
+}
+
+/** Mirror the framework's inject choreography: bake a real instance from the
+ * declared handle and hand its actions to the entry's inject factory. */
+function faceOf(slots: SlotsService) {
+  const entry = slots.entries(SLOT).find(e => e.component === LanguageRow)!
+  const handle = entry.store as ReturnType<typeof createLanguageRowStore>
+  const instance = handle.create()
+  const face = (entry.inject as unknown as (a: typeof instance.actions) => LanguageRowInjected)(instance.actions)
+  return { entry, instance, face }
+}
+
+describe('locale apply', () => {
+  it('declares the slot service', () => {
+    expect(inject).toEqual(['slots'])
+  })
+
+  it('provides the service with base + settings dictionaries and registers the row (declaration before or after apply)', async () => {
+    const before = await bench()
+    declareItems(before.slots)
+    await before.ctx.plugin({ inject: [...inject], apply }).await()
+    const locale = before.ctx.get('locale') as LocaleService
+    // Base dictionaries are registered: the (ns, locale) seats are occupied.
+    expect(() => locale.register('common', 'zh', {})).toThrow('already has locale')
+    expect(() => locale.register('common', 'en', {})).toThrow('already has locale')
+    expect(locale.bind(SETTINGS_NS)('language.title')).toBe('语言')
+    const entry = before.slots.entries(SLOT).find(e => e.component === LanguageRow)!
+    expect(entry.options).toMatchObject({ id: 'language', order: 0 })
+
+    const after = await bench()
+    const fiber = after.ctx.plugin({ inject: [...inject], apply })
+    await fiber.await()
+    expect(after.slots.entries(SLOT)).toHaveLength(0)
+    declareItems(after.slots)
+    await Promise.resolve()
+    expect(after.slots.entries(SLOT).some(e => e.component === LanguageRow)).toBe(true)
+  })
+
+  it('projects service snapshots into the row store and routes face writes back', async () => {
+    const b = await bench()
+    declareItems(b.slots)
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    const locale = b.ctx.get('locale') as LocaleService
+    // An event ahead of any inject hits the unbound-actions arm.
+    locale.setLocale('en')
+
+    const { instance, face } = faceOf(b.slots)
+    // The inject-time re-sync sealed the init window: the mirror is current.
+    expect(instance.getSnapshot().active).toBe('en')
+    expect(instance.getSnapshot().options.map(o => o.id)).toEqual(['zh', 'en'])
+    expect(face.t('language.title')).toBe('Language')
+
+    face.setLocale('zh')
+    expect(locale.getLocale().active).toBe('zh')
+    expect(instance.getSnapshot().active).toBe('zh')
+    expect(face.t('language.title')).toBe('语言')
+  })
+
+  it('recovers after an HMR collapse of the declaring entry (stale disposer must not block)', async () => {
+    const b = await bench()
+    const host = declareItems(b.slots)
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    expect(b.slots.entries(SLOT)).toHaveLength(1)
+
+    // Collapse: the declarer dies, the cascade removes our entry while the
+    // apply closure still holds its (now stale) disposer.
+    host()
+    expect(b.slots.entries(SLOT)).toHaveLength(0)
+
+    declareItems(b.slots)
+    await Promise.resolve()
+    expect(b.slots.entries(SLOT).some(e => e.component === LanguageRow)).toBe(true)
+  })
+
+  it('teardown removes the row; teardown without a declaration is quiet', async () => {
+    const b = await bench()
+    declareItems(b.slots)
+    const fiber = b.ctx.plugin({ inject: [...inject], apply })
+    await fiber.await()
+    expect(b.slots.entries(SLOT)).toHaveLength(1)
+    await fiber.dispose()
+    expect(b.slots.entries(SLOT)).toHaveLength(0)
+
+    // Never-declared bench: the effect disposer's dispose arm stays undefined.
+    const quiet = await bench()
+    const f2 = quiet.ctx.plugin({ inject: [...inject], apply })
+    await f2.await()
+    await f2.dispose()
+    expect(quiet.slots.entries(SLOT)).toHaveLength(0)
+  })
+})

packages/client/locale/tests/invariant.spec.ts

@@ -0,0 +1,34 @@
+// @vitest-environment jsdom
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import { apply as nodeApply } from '@deepseek-ai/dsh-client-locale'
+import { apply as clientApply, COMMON_NS, LocaleService, inject } from '@deepseek-ai/dsh-client-locale/client'
+import * as LocaleInvariant from '@deepseek-ai/dsh-client-locale/invariant'
+import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
+import InvariantService from '@deepseek-ai/dsh-invariants'
+
+describe('invariant companion', () => {
+  it('registers under the package name with an empty installer', async () => {
+    const ctx = new Context()
+    await ctx.plugin(InvariantService, { enabled: true })
+    await expect(ctx.plugin(LocaleInvariant).await()).resolves.toBeDefined()
+  })
+
+  it('node-half apply is a no-op host placeholder', () => {
+    nodeApply()
+    expect(true).toBe(true) // reaching here without throw is the contract
+  })
+
+  it('client apply provides ctx.locale seeded with the zh/en common namespace', async () => {
+    // The feature registers its own Language settings row, hence the slots edge.
+    expect(inject).toEqual(['slots'])
+    const ctx = new Context()
+    new SlotsService(ctx)
+    await ctx.plugin({ inject, apply: clientApply }).await()
+    const locale = ctx.get('locale')
+    expect(locale).toBeInstanceOf(LocaleService)
+    // Seeded dictionaries occupy the (ns, locale) seats even while empty.
+    expect(() => (locale as LocaleService).register(COMMON_NS, 'zh', {})).toThrow('already has locale')
+    expect(() => (locale as LocaleService).register(COMMON_NS, 'en', {})).toThrow('already has locale')
+  })
+})

packages/client/locale/tests/language-row.spec.tsx

@@ -0,0 +1,82 @@
+// @vitest-environment jsdom
+/** LanguageRow behavior: selector pill shows the active locale, the menu
+ * opens/closes, and selection drives setLocale. */
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { act, cleanup, fireEvent, render, screen } from '@testing-library/react'
+import { createSnapshotStore, type SessionListState, type WorkspaceListState } from '@deepseek-ai/dsh-client-runtime/client'
+import { bindSnapshotSelector } from '@deepseek-ai/dsh-client-web-react'
+import { LanguageRow } from '../src/client/LanguageRow.tsx'
+import type { LanguageRowComponentProps } from '../src/client/LanguageRow.tsx'
+import { createLanguageRowStore } from '../src/client/settings-store.ts'
+
+afterEach(cleanup)
+
+const OPTIONS = [{ id: 'zh', label: '中文' }, { id: 'en', label: 'English' }]
+
+/** Empty global standard-kit hooks (the row reads neither). */
+function emptySessions() {
+  const store = createSnapshotStore<SessionListState>(
+    { ids: [], byId: {}, current: undefined, phase: 'ready' })
+  return bindSnapshotSelector(store)
+}
+function emptyWorkspaces() {
+  const store = createSnapshotStore<WorkspaceListState>({
+    items: [], state: 'idle', phase: 'ready', error: null,
+    baselinesReady: true, recentWorkspaceId: undefined,
+  })
+  return bindSnapshotSelector(store)
+}
+
+function mount(active = 'en') {
+  // Real store instance — the sanctioned zero-machinery path for tests.
+  const store = createLanguageRowStore().create()
+  store.actions.sync(active, OPTIONS, 0)
+  const setLocale = vi.fn()
+  const props: LanguageRowComponentProps = {
+    useSessions: emptySessions(),
+    useWorkspaces: emptyWorkspaces(),
+    useStore: bindSnapshotSelector(store),
+    actions: store.actions,
+    t: (key: string) => key === 'language.title' ? 'Language' : key,
+    setLocale,
+  }
+  render(<LanguageRow {...props} />)
+  return { store, setLocale }
+}
+
+describe('LanguageRow', () => {
+  it('shows the title and the active locale label on the selector pill', () => {
+    mount('en')
+    expect(screen.getByText('Language')).toBeDefined()
+    const trigger = screen.getByRole('button', { name: /English/ })
+    expect(trigger.getAttribute('aria-expanded')).toBe('false')
+  })
+
+  it('opens the menu, selects a locale, and closes', () => {
+    const b = mount('en')
+    const trigger = screen.getByRole('button', { name: /English/ })
+    fireEvent.click(trigger)
+    expect(trigger.getAttribute('aria-expanded')).toBe('true')
+    fireEvent.click(screen.getByRole('menuitem', { name: '中文' }))
+    expect(b.setLocale).toHaveBeenCalledWith('zh')
+    expect(trigger.getAttribute('aria-expanded')).toBe('false')
+    expect(screen.queryByRole('menuitem', { name: '中文' })).toBeNull()
+  })
+
+  it('closes on outside pointerdown without selecting', () => {
+    const b = mount('en')
+    fireEvent.click(screen.getByRole('button', { name: /English/ }))
+    expect(screen.getByRole('menuitem', { name: '中文' })).toBeDefined()
+    fireEvent.pointerDown(document.body)
+    expect(screen.queryByRole('menuitem', { name: '中文' })).toBeNull()
+    expect(b.setLocale).not.toHaveBeenCalled()
+  })
+
+  it('follows store changes; an unknown active id falls back to the id itself', () => {
+    const b = mount('en')
+    act(() => { b.store.actions.sync('zh', OPTIONS, 1) })
+    expect(screen.getByRole('button', { name: /中文/ })).toBeDefined()
+    act(() => { b.store.actions.sync('fr', OPTIONS, 2) })
+    expect(screen.getByRole('button', { name: /fr/ })).toBeDefined()
+  })
+})

packages/client/locale/tests/locale.spec.ts

@@ -0,0 +1,102 @@
+// @vitest-environment jsdom
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { Context } from 'cordis'
+import type { LocaleSnapshot } from '@deepseek-ai/dsh-client-locale/client'
+import { LocaleService, STORAGE_KEY } from '@deepseek-ai/dsh-client-locale/client'
+
+const make = (): { ctx: Context; svc: LocaleService; events: LocaleSnapshot[] } => {
+  const ctx = new Context()
+  const events: LocaleSnapshot[] = []
+  ctx.on('locale/change', (snapshot) => { events.push(snapshot) })
+  return { ctx, svc: new LocaleService(ctx), events }
+}
+
+describe('LocaleService', () => {
+  beforeEach(() => {
+    localStorage.clear()
+  })
+
+  it('translates through the active-locale -> zh -> key chain', () => {
+    const { svc } = make()
+    svc.register('ns', 'zh', { hello: '你好', onlyZh: '仅中文' })
+    svc.register('ns', 'en', { hello: 'Hello' })
+    const t = svc.bind('ns')
+    expect(svc.getLocale().active).toBe('zh')
+    expect(t('hello')).toBe('你好')
+    svc.setLocale('en')
+    expect(t('hello')).toBe('Hello')
+    expect(t('onlyZh')).toBe('仅中文')
+    expect(t('missing.key')).toBe('missing.key')
+  })
+
+  it('interpolates {name} params and leaves unknown placeholders intact', () => {
+    const { svc } = make()
+    svc.register('ns', 'zh', { greet: '你好，{name}！第 {n} 次', partial: '{known} 与 {unknown}' })
+    const t = svc.bind('ns')
+    expect(t('greet', { name: '世界', n: 2 })).toBe('你好，世界！第 2 次')
+    expect(t('partial', { known: 'A' })).toBe('A 与 {unknown}')
+  })
+
+  it('bind returns a stable per-namespace function identity', () => {
+    const { svc } = make()
+    expect(svc.bind('a')).toBe(svc.bind('a'))
+    expect(svc.bind('a')).not.toBe(svc.bind('b'))
+  })
+
+  it('rejects duplicate (ns, locale) and disposer only removes its own dict', () => {
+    const { svc } = make()
+    const dispose = svc.register('ns', 'zh', { k: 'v1' })
+    expect(() => svc.register('ns', 'zh', { k: 'v2' })).toThrow('already has locale')
+    dispose()
+    const t = svc.bind('ns')
+    expect(t('k')).toBe('k')
+    svc.register('ns', 'zh', { k: 'v2' })
+    expect(t('k')).toBe('v2')
+    dispose()
+    expect(t('k')).toBe('v2')
+  })
+
+  it('setLocale persists, republishes an immutable snapshot, and no-ops on same value', () => {
+    const { svc, events } = make()
+    svc.setLocale('en')
+    expect(svc.getLocale().active).toBe('en')
+    expect(localStorage.getItem(STORAGE_KEY)).toBe('en')
+    expect(events).toHaveLength(1)
+    expect(events[0]).toBe(svc.getLocale())
+    expect(events[0]!.revision).toBe(1)
+    svc.setLocale('en')
+    expect(events).toHaveLength(1)
+  })
+
+  it('throws on unknown locale ids', () => {
+    const { svc } = make()
+    expect(() => { svc.setLocale('fr') }).toThrow('not registered')
+  })
+
+  it('restores a persisted locale and falls back to zh on garbage', () => {
+    localStorage.setItem(STORAGE_KEY, 'en')
+    expect(make().svc.getLocale().active).toBe('en')
+    localStorage.setItem(STORAGE_KEY, 'fr')
+    expect(make().svc.getLocale().active).toBe('zh')
+  })
+
+  it('runs without localStorage (node boots): defaults on read, no-op on write', () => {
+    vi.stubGlobal('localStorage', undefined)
+    try {
+      const { svc } = make()
+      expect(svc.getLocale().active).toBe('zh')
+      svc.setLocale('en')
+      expect(svc.getLocale().active).toBe('en')
+    } finally {
+      vi.unstubAllGlobals()
+    }
+  })
+
+  it('exposes the two shipped locales with self-described labels', () => {
+    const { svc } = make()
+    expect(svc.getLocale().locales).toEqual([
+      { id: 'zh', label: '中文' },
+      { id: 'en', label: 'English' },
+    ])
+  })
+})

packages/client/locale/tests/settings-store.spec.ts

@@ -0,0 +1,30 @@
+/** Language row store: snapshot-mirror action and the revision guard. */
+import { describe, expect, it } from 'vitest'
+import { createLanguageRowStore } from '../src/client/settings-store.ts'
+
+const OPTIONS = [{ id: 'zh', label: '中文' }, { id: 'en', label: 'English' }]
+
+describe('createLanguageRowStore', () => {
+  it('init shape: empty mirror with revision at -1', () => {
+    const store = createLanguageRowStore().create()
+    expect(store.getSnapshot()).toEqual({ active: '', options: [], revision: -1 })
+  })
+
+  it('sync mirrors the snapshot and advances the revision', () => {
+    const store = createLanguageRowStore().create()
+    store.actions.sync('zh', OPTIONS, 0)
+    expect(store.getSnapshot()).toEqual({ active: 'zh', options: OPTIONS, revision: 0 })
+    store.actions.sync('en', OPTIONS, 1)
+    expect(store.getSnapshot().active).toBe('en')
+    expect(store.getSnapshot().revision).toBe(1)
+  })
+
+  it('revision guard drops stale and duplicate writes', () => {
+    const store = createLanguageRowStore().create()
+    store.actions.sync('en', OPTIONS, 5)
+    store.actions.sync('zh', OPTIONS, 4)
+    store.actions.sync('zh', OPTIONS, 5)
+    expect(store.getSnapshot().active).toBe('en')
+    expect(store.getSnapshot().revision).toBe(5)
+  })
+})

packages/client/locale/tsconfig.json

@@ -0,0 +1,27 @@
+{
+  "extends": "../../../tsconfig.base.client.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../runtime"
+    },
+    {
+      "path": "../ui-primitives"
+    },
+    {
+      "path": "../ui-slots"
+    },
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../../support/invariants"
+    }
+  ]
+}

packages/client/locale/tsdown.config.ts

@@ -0,0 +1,3 @@
+import { clientBundle } from '../tsdown.client.ts'
+
+export default clientBundle('@deepseek-ai/dsh-client-locale', ['lib/types/index.js', 'lib/types/invariant.js'])

packages/client/modules/README.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+README.md: efba9e2eb0b148677fc7ac18bfad6333fb6f80da
+README.zh.md: 7d1aa8af08256c47c1ae65343e46c30e910128d0

packages/client/modules/README.md

@@ -0,0 +1,22 @@
+# @deepseek-ai/dsh-client-modules
+
+English | [中文](README.zh.md)
+
+Client module system: the browser peer of Node's internal ESM loader, built as a lazy CJS table. The web shell mounts the vendored cordis Loader for entry governance (fiber lifecycle, inject waiting, update/refresh) and injects this package's `ClientModuleLoader` as its `internal` seam — the vendored side's only consumption point is `EntryTree.import`, so replacing `internal` replaces exactly "how plugin code arrives" and nothing else.
+
+Lazy CJS model (web2): executing a plugin bundle only REGISTERS its factory (`window.__ModuleLoader__.load({id, factory})`); every module body side effect — CSS injection included — lives in the factory closure and runs at materialization (`factory(require)` → export surface, memoized in `loadCache`), not at script execution. A factory that requires another registered-but-unmaterialized module materializes it recursively, so load order needs no external sequencing; require cycles throw (factory-form CJS cannot deliver partial exports). `<id>/client` and the bare id name the same surface (a plugin bundle IS its package's client half).
+
+Resolution branch order (`import(specifier)`): platform seed word → shell instance; memoized record → surface; shell-own static registry (`registerStatic`, app-shell) → module; registered factory → materialize; graph row (`window.__DSH_BOOT__`) → fetch + execute + materialize; anything else throws — the runtime mirror of the build-time bundle purity gate. The synchronous `require` handed to factories walks the same order minus the fetch branch and records observed edges into the module record. `prefetch` is the stage-one arrival hook (fetch + execute, registration only; concurrent calls share one in-flight task); `invalidate` drops the factory and the materialized record so the next prefetch/import refetches (the HMR hook).
+
+## Model Experience
+
+None, as the module loader is browser-side kernel machinery; nothing here reaches a model request.
+
+#### KV Cache effect
+
+None; this package neither assembles nor sends a provider request.
+
+## Known Limitations and Deferred Work
+
+- **Flat module graph by design** — every bundle is one module node whose edges point only at table leaves; the interface (loadCache/edges/invalidate) is shaped for a general module graph so the externalization granularity can change without an interface change.
+- **No unload bookkeeping of its own** — style removal and fiber teardown ordering live with the HMR driver (`@deepseek-ai/dsh-client-hmr`); the loader only inventories owned style tag ids per record.

packages/client/modules/README.zh.md

@@ -0,0 +1,22 @@
+# @deepseek-ai/dsh-client-modules
+
+[English](README.md) | 中文
+
+客户端模块系统：Node 内部 ESM loader 的浏览器端对等实现，以惰性 CJS 表构建。web 外壳挂载 vendored cordis Loader 来治理配置项（fiber 生命周期、inject 等待、update/refresh），并把该包的 `ClientModuleLoader` 作为其 `internal` seam 注入；vendored 一侧唯一的消费点是 `EntryTree.import`，因此替换 `internal` 恰好只会替换「插件代码如何到达」，不会改变其他内容。
+
+惰性 CJS 模型（web2）：执行插件组合包只会注册其 factory（`window.__ModuleLoader__.load({id, factory})`）；每个模块主体的副作用（包括 CSS 注入）都位于 factory 闭包中，在物化时运行（`factory(require)` → 导出表层，并在 `loadCache` 中记忆化），不会在脚本执行时运行。如果 factory 请求另一个已注册但尚未物化的模块，系统会递归物化它，因此加载顺序无需外部编排；require 循环会抛出异常（factory 形式的 CJS 无法交付部分导出）。`<id>/client` 与裸 id 指向同一表层（一个插件组合包就是其包的客户端侧）。
+
+解析分支顺序（`import(specifier)`）：平台种子词 → 外壳实例；记忆化记录 → 表层；外壳自身的静态注册表（`registerStatic`，app-shell）→ 模块；已注册 factory → 物化；图行（`window.__DSH_BOOT__`）→ 抓取 + 执行 + 物化；其他情况一律抛出异常。这是构建时组合包纯度门禁的运行时镜像。交给 factory 的同步 `require` 采用相同顺序，但不含抓取分支，并把观察到的边记录到模块记录中。`prefetch` 是第一阶段到达 hook（抓取 + 执行，只注册；并发调用共享一个进行中的 task）；`invalidate` 会丢弃 factory 与物化记录，使下一次 prefetch/import 重新抓取（HMR hook）。
+
+## 模型体验
+
+无。模块 loader 属于浏览器侧内核机制；这里没有任何内容进入模型请求。
+
+#### KV Cache 影响
+
+无；该包既不组装也不发送提供方请求。
+
+## 已知限制与暂缓事项
+
+- **有意采用扁平模块图**：每个组合包是一个模块节点，其边只指向表叶；接口（loadCache/edges/invalidate）按通用模块图塑形，因此可以改变 externalization 粒度而不更改接口。
+- **自身不记录卸载账目**：样式移除与 fiber 拆卸顺序属于 HMR 驱动器（`@deepseek-ai/dsh-client-hmr`）；loader 只逐记录清点自身拥有的样式标签 id。

packages/client/modules/package.json

@@ -1,6 +1,6 @@
 {
-  "name": "@deepseek-ai/dsh-client-i18n",
-  "description": "i18n plugin: I18nService (ns x locale dictionaries, bind(ns) -> t, locale store); zh/en skeleton",
+  "name": "@deepseek-ai/dsh-client-modules",
+  "description": "Client module system, dual-face: node half composes the __DSH_BOOT__ entry graph (incremental dshClient scan, bundle route, index tap, webPlugins service); browser half is the lazy-CJS module table the vendored cordis Loader consumes as its internal seam",
   "version": "0.0.1",
   "private": true,
   "type": "module",
@@ -11,20 +11,20 @@
       "types": "./lib/types/index.d.ts",
       "default": "./lib/index.js"
     },
-    "./invariant": {
-      "types": "./lib/types/invariant.d.ts",
-      "default": "./lib/invariant.js"
-    },
     "./client": {
       "types": "./lib/types/client/index.d.ts",
       "default": "./lib/client.js"
     },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
     "./src/*": "./src/*",
     "./package.json": "./package.json"
   },
   "dshClient": {
-    "inject": [],
     "platform": "web",
+    "inject": [],
     "immediately": true
   },
   "scripts": {
@@ -32,14 +32,9 @@
     "watch": "tsdown --watch"
   },
   "license": "BSD-3-Clause",
-  "dependencies": {
-    "@deepseek-ai/dsh-client-web-react": "workspace:^"
-  },
-  "peerDependencies": {
-    "@deepseek-ai/dsh-invariants": "^0.0.1",
-    "cordis": "^4.0.0-rc.7"
-  },
   "devDependencies": {
+    "@cordisjs/plugin-loader": "workspace:^",
+    "@deepseek-ai/dsh-host-webserver": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "cordis": "^4.0.0-rc.7"
   },
@@ -50,5 +45,9 @@
     "lib/types/**/*.d.ts",
     "lib/types/**/*.d.ts.map",
     "src"
-  ]
+  ],
+  "peerDependencies": {
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "cordis": "^4.0.0-rc.7"
+  }
 }

packages/client/modules/src/client/index.ts

@@ -0,0 +1,34 @@
+/**
+ * Browser half (the standard `./client` export): the module-system class and
+ * wire contract, plus the enrollment plugin face. The module system itself is
+ * built by the shell kernel BEFORE cordis exists (the bootstrap exception,
+ * design §4.7 — the mechanism that loads plugins cannot arrive through
+ * itself); the plugin face only enrolls that pre-existing instance by
+ * providing it as `ctx.modules`. The kernel statically registers this module,
+ * so the graph row for this package never triggers a real fetch — arrival is
+ * a no-op against the already-registered entry.
+ * @module @deepseek-ai/dsh-client-modules/client
+ */
+import type { Context } from 'cordis'
+import type { DshWindow } from './manifest.ts'
+
+export { ClientModuleSystem } from './system.ts'
+export { parseBootManifest } from './manifest.ts'
+export type {
+  BootManifest, BootModuleRow, BootPluginRow, ClientModuleLoader, ClientModuleRecord,
+  ClientModuleSystemOptions, ClientPluginHandoff, DshWindow, WebBootEntry, WebBootGraph,
+} from './manifest.ts'
+
+/**
+ * Enroll the kernel-built module system as `ctx.modules`.
+ * @param ctx - client root context.
+ */
+export function apply(ctx: Context): void {
+  const modules = (globalThis as DshWindow).__DSH_MODULES__
+  // The kernel writes the slot right after constructing the instance, before
+  // any cordis entry exists — a missing slot means the kernel sequencing broke.
+  if (modules === undefined) {
+    throw new Error('client-modules: window.__DSH_MODULES__ missing — the shell kernel must construct the module system before plugin boot')
+  }
+  ctx.reflect.provide('modules', modules)
+}

packages/client/modules/src/client/manifest.ts

@@ -0,0 +1,243 @@
+/**
+ * Client module system: the browser peer of Node's internal ESM loader, built
+ * as a lazy CJS table. The vendored cordis Loader consumes this object
+ * through its `internal` seam (the only call site is `EntryTree.import` →
+ * `internal.import`), which keeps entry governance (fiber lifecycle, inject
+ * waiting, update/refresh) entirely on the vendored side while this package
+ * owns code arrival.
+ *
+ * Lazy CJS model (web2 §0): executing a plugin bundle only REGISTERS its
+ * factory (`window.__ModuleLoader__.load({id, factory})`); every module body
+ * side effect — including CSS injection — lives inside the factory closure
+ * and runs at materialization, not at script execution. Materialization
+ * (factory(require) → export surface) happens on first import/require and is
+ * memoized in {@link ClientModuleLoader.loadCache}; a factory that requires
+ * another registered-but-unmaterialized module materializes it recursively,
+ * so load order needs no external sequencing.
+ *
+ * Resolution branch order (import): seed word → shell instance; memoized
+ * record → surface; static registry (shell-own modules, e.g. app-shell) →
+ * module; registered factory → materialize; graph row → fetch + execute +
+ * materialize; anything else → throw (loud — the runtime mirror of the
+ * build-time bundle purity gate). The synchronous `require` handed to
+ * factories walks the same order minus the fetch branch: fetching is async,
+ * so only already-executed bundles can be required — and cross-plugin value
+ * imports are a build error anyway.
+ *
+ * This file is the browser-safe contract face (zero node imports): the
+ * `__DSH_BOOT__` wire types, the boot-manifest parser, and the seams around
+ * {@link ClientModuleSystem}. The package root is the host-side service that
+ * composes the wire.
+ */
+
+import type {} from 'cordis'
+import type { ClientModuleSystem } from './system.ts'
+
+declare module 'cordis' {
+  interface Context {
+    /** The client module system the web shell builds at boot (contract C5; provided by the `./client` wrapper plugin). */
+    modules: ClientModuleLoader
+  }
+}
+
+/**
+ * One composed client entry pushed by the host (web2 §0 graph row). Wire
+ * single source: the host node half (package root) produces this same shape.
+ * `immediately` marks stage-one prefetch; `inject` is informational graph
+ * metadata (the authoritative edges live in each package's dshClient
+ * declaration and reach fibers through entry creation).
+ */
+export interface WebBootEntry {
+  /** Entry name == package name. */
+  id: string
+  /** Bundle endpoint, '/plugins/<id>/client.js?rev=<rev>'. */
+  url: string
+  /** Bundle content hash (cache-busting consistency anchor). */
+  rev: string
+  /** Package-name dependency edges, informational (preflight display / HMR diffing). */
+  inject?: string[]
+  /** Stage-one prefetch mark: fetch + execute (factory registration) during module-face boot. */
+  immediately?: boolean
+}
+
+/** The composed client entry graph the host injects as `window.__DSH_BOOT__`. */
+export interface WebBootGraph {
+  /** Consistency anchor over the whole graph (content + bundle hashes). */
+  rev: string
+  /** Composed entries; order carries no semantics (activation order is fiber inject waiting). */
+  entries: WebBootEntry[]
+}
+
+/** The npm-package view of one boot row: what the module table needs to fetch the bundle. */
+export interface BootModuleRow {
+  /** Entry name == package name (module-table key). */
+  id: string
+  /** Bundle endpoint, '/plugins/<id>/client.js?rev=<rev>'. */
+  url: string
+  /** Bundle content hash. */
+  rev: string
+}
+
+/** The cordis-plugin view of one boot row: what entry composition needs (optional wire fields normalized). */
+export interface BootPluginRow {
+  /** Entry name == package name. */
+  id: string
+  /** Package-name dependency edges ([] when the wire omits them). */
+  inject: string[]
+  /** Stage-one prefetch tier (false when the wire omits it). */
+  immediately: boolean
+}
+
+/** The parsed boot manifest: one wire, two consumer views. */
+export interface BootManifest {
+  /** Consistency anchor over the whole graph. */
+  rev: string
+  /** Rows as the module table consumes them. */
+  modules: BootModuleRow[]
+  /** Rows as entry composition consumes them. */
+  plugins: BootPluginRow[]
+}
+
+/**
+ * Parse `window.__DSH_BOOT__` into the two consumer views. Wire boundary:
+ * a missing or malformed graph throws (the shell shows the loud failure —
+ * a page without a valid manifest cannot boot anything).
+ * @param wire - the raw `window.__DSH_BOOT__` value.
+ * @returns the manifest with optional plugin-view fields normalized.
+ */
+export function parseBootManifest(wire: unknown): BootManifest {
+  if (typeof wire !== 'object' || wire === null) {
+    throw new Error('client-modules: window.__DSH_BOOT__ is missing or not an object')
+  }
+  const graph = wire as Record<string, unknown>
+  if (typeof graph.rev !== 'string') {
+    throw new Error('client-modules: boot manifest rev must be a string')
+  }
+  if (!Array.isArray(graph.entries)) {
+    throw new Error('client-modules: boot manifest entries must be an array')
+  }
+  const modules: BootModuleRow[] = []
+  const plugins: BootPluginRow[] = []
+  for (const value of graph.entries as unknown[]) {
+    if (typeof value !== 'object' || value === null) {
+      throw new Error('client-modules: boot manifest entry is not an object')
+    }
+    const row = value as Record<string, unknown>
+    const where = typeof row.id === 'string' ? `"${row.id}"` : JSON.stringify(row)
+    if (typeof row.id !== 'string' || typeof row.url !== 'string' || typeof row.rev !== 'string') {
+      throw new Error(`client-modules: boot manifest entry ${where} must carry string id/url/rev`)
+    }
+    if (row.inject !== undefined && (!Array.isArray(row.inject) || row.inject.some(i => typeof i !== 'string'))) {
+      throw new Error(`client-modules: boot manifest entry ${where} inject must be a string array`)
+    }
+    if (row.immediately !== undefined && typeof row.immediately !== 'boolean') {
+      throw new Error(`client-modules: boot manifest entry ${where} immediately must be a boolean`)
+    }
+    modules.push({ id: row.id, url: row.url, rev: row.rev })
+    plugins.push({
+      id: row.id,
+      inject: row.inject === undefined ? [] : [...row.inject as string[]],
+      immediately: row.immediately === true,
+    })
+  }
+  return { rev: graph.rev, modules, plugins }
+}
+
+/** The shape a client bundle hands to `window.__ModuleLoader__.load` (registration handoff, contract C6). */
+export interface ClientPluginHandoff {
+  /** Plugin id (package name) — the registration key; must match the graph row being executed. */
+  id: string
+  /**
+   * Closure factory holding the whole bundle body: receives the synchronous
+   * require bound to the module table and returns the bundle's export
+   * surface. Runs once, at materialization.
+   */
+  factory: (require: (spec: string) => unknown) => Record<string, unknown>
+}
+
+/** Window surface of the web boot protocol: the host-injected graph, the registration sink, and the kernel handoff slot. */
+export interface DshWindow {
+  /** Host-composed entry graph, injected before the shell bundle runs; wire-boundary raw until {@link parseBootManifest}. */
+  __DSH_BOOT__?: unknown
+  /** Bundle registration sink; installed once per page by the {@link ClientModuleSystem} constructor (contract C6). */
+  __ModuleLoader__?: { load(handoff: ClientPluginHandoff): void }
+  /**
+   * Kernel handoff slot: the shell kernel stores the instance here right
+   * after construction (before cordis exists) so the `./client` wrapper
+   * plugin can provide it as `ctx.modules`. Missing slot at wrapper apply
+   * time = kernel sequencing bug, thrown loud.
+   */
+  __DSH_MODULES__?: ClientModuleSystem
+}
+
+/** Per-module bookkeeping in {@link ClientModuleLoader.loadCache} (module-graph seam, flat today). */
+export interface ClientModuleRecord {
+  /** Module id (entry name / package name). */
+  id: string
+  /** The materialized export surface (factory `module.exports`, or the shell module for static registrations). */
+  surface: unknown
+  /** Owned `<style data-plugin>` tag ids (`data-plugin-css` values) injected during materialization. */
+  styles: string[]
+  /** Observed `require()` edges (module-graph seam; only table words can appear today). */
+  edges: Set<string>
+}
+
+/**
+ * The internal-seam subset the vendored Loader and the client HMR plugin
+ * consume. Mounted on `ctx.loader.internal` by the shell boot and provided
+ * as `ctx.modules` (contract C5).
+ */
+export interface ClientModuleLoader {
+  /** Discriminant against Node's internal loader shapes ('v1'/'v2'). */
+  version: 'client'
+  /** Materialized-module registry: id → record. The governance-side read face for entry export surfaces. */
+  loadCache: Map<string, ClientModuleRecord>
+  /**
+   * Internal seam consumed by the vendored Loader's `tree.import`. Resolves
+   * `specifier` through the branch order documented on the module, fetching
+   * and executing a bundle when needed.
+   * @param specifier - module specifier (entry name or table word).
+   * @param parentURL - importer URL (unused — the client module graph is flat).
+   * @param attrs - import attributes (unused; interface parity with Node's seam).
+   * @returns the module's export surface.
+   */
+  import(specifier: string, parentURL: string, attrs: Record<string, unknown>): Promise<unknown>
+  /**
+   * Register a shell-own module (app-shell — code that ships inside the shell
+   * bundle and never arrives as a plugin bundle).
+   * @param id - entry name (shell-owned pseudo id).
+   * @param module - the statically imported module namespace.
+   */
+  registerStatic(id: string, module: unknown): void
+  /**
+   * Stage-one arrival: fetch the entry's bundle and execute it, registering
+   * its factory (no materialization — module side effects wait for import).
+   * No-op for static-registered ids and ids whose factory is already
+   * registered; concurrent calls share one in-flight task. To force a fresh
+   * fetch (HMR), {@link invalidate} first.
+   * @param id - graph entry name.
+   */
+  prefetch(id: string): Promise<void>
+  /**
+   * Full reset of one module: drop its registered factory, its materialized
+   * record, and any consumed bundle text, so the next prefetch/import
+   * refetches and re-executes (the HMR invalidation hook).
+   * @param id - entry name to invalidate.
+   */
+  invalidate(id: string): void
+}
+
+/** Options for {@link ClientModuleSystem} (assembled by the web shell kernel at boot). */
+export interface ClientModuleSystemOptions {
+  /** Boot rows in the module-table view (from {@link parseBootManifest}). */
+  modules: BootModuleRow[]
+  /** Module-table seed: platform-singleton specifier → shell instance. */
+  staticModules: Record<string, unknown>
+  /** Bundle fetch seam (parallelizable half). Defaults to same-origin fetch().text(). */
+  fetchBundle?: (url: string) => Promise<string>
+  /**
+   * Bundle execution seam (synchronously performs the load() registration).
+   * Defaults to a <script> element carrying the code.
+   */
+  executeBundle?: (code: string, url: string) => void
+}

packages/client/modules/src/client/system.ts

@@ -0,0 +1,231 @@
+/**
+ * ClientModuleSystem — the implementation behind the {@link ClientModuleLoader}
+ * seam. The conceptual contract (lazy CJS model, resolution branch order) is
+ * documented on the public interfaces in `./manifest.ts`; this file owns the
+ * state tables and the fetch/execute/materialize machinery.
+ */
+import type {
+  BootModuleRow, ClientModuleLoader, ClientModuleRecord,
+  ClientModuleSystemOptions, ClientPluginHandoff, DshWindow,
+} from './manifest.ts'
+
+/** A registered-but-unmaterialized bundle: the factory plus its source URL (diagnostics). */
+interface RegisteredFactory {
+  factory: ClientPluginHandoff['factory']
+  url: string
+}
+
+/** Default bundle fetch seam: same-origin fetch().text(). */
+const defaultFetchBundle = async (url: string): Promise<string> => {
+  const res = await fetch(url)
+  if (!res.ok) throw new Error(`client-modules: bundle fetch ${url} answered ${String(res.status)}`)
+  return res.text()
+}
+
+/** Default bundle execution seam: a <script> element carrying the code. */
+const defaultExecuteBundle = (code: string, url: string): void => {
+  const el = document.createElement('script')
+  // Inline execution (not src) so the fetch half stays parallelizable; the
+  // sourceURL comment keeps devtools stack frames attributed to the bundle.
+  el.textContent = `${code}\n//# sourceURL=${url}`
+  document.head.appendChild(el)
+  // Execution is synchronous for inline scripts: the factory is registered by
+  // now, so the node (and its source text) has no further job. Removing it
+  // keeps repeated HMR rebuilds from accumulating dead script nodes.
+  el.remove()
+}
+
+/**
+ * A plugin bundle IS its package's client half: `<id>/client` (the exports
+ * subpath external bundles emit) and the bare graph id name the same
+ * surface, so table lookups normalize the suffix away.
+ */
+const stripClientSuffix = (spec: string): string =>
+  spec.endsWith('/client') ? spec.slice(0, -'/client'.length) : spec
+
+/**
+ * Claim and inventory the <style> tags a factory injected during
+ * materialization: preset-emitted tags arrive pre-tagged with data-plugin;
+ * any untagged tag is claimed for the materializing plugin (HMR bookkeeping).
+ */
+const claimStyles = (id: string): string[] => {
+  if (typeof document === 'undefined') return []
+  for (const el of document.querySelectorAll('style:not([data-plugin])')) {
+    el.setAttribute('data-plugin', id)
+  }
+  const owned: string[] = []
+  for (const el of document.querySelectorAll(`style[data-plugin=${JSON.stringify(id)}]`)) {
+    owned.push(el.getAttribute('data-plugin-css') ?? id)
+  }
+  return owned
+}
+
+/**
+ * The client module system: state tables plus the arrival/materialization
+ * machinery implementing {@link ClientModuleLoader} (whose members carry the
+ * seam contract docs). Construction indexes the boot rows and installs the
+ * `window.__ModuleLoader__` registration sink (contract C6) — once per page.
+ */
+export class ClientModuleSystem implements ClientModuleLoader {
+  readonly version = 'client'
+  readonly loadCache = new Map<string, ClientModuleRecord>()
+
+  private readonly seed: Map<string, unknown>
+  private readonly statics = new Map<string, unknown>()
+  private readonly factories = new Map<string, RegisteredFactory>()
+  /** In-flight prefetch (fetch + execute) per id; concurrent callers share it. */
+  private readonly pendingArrival = new Map<string, Promise<void>>()
+  /** Materialization re-entrancy guard: factory-form CJS cannot deliver partial exports, so a cycle is fatal. */
+  private readonly materializing = new Set<string>()
+  private readonly graphRows = new Map<string, BootModuleRow>()
+  // Execution URL of the bundle currently being executed (bound into the
+  // factory registration so diagnostics can name the source).
+  private executingUrl = ''
+  // Graph id of the row currently being executed ('' outside arrive):
+  // the load sink cross-checks the handoff id against it so a mis-stamped
+  // bundle cannot register under another entry's identity.
+  private executingId = ''
+
+  private readonly fetchBundle: (url: string) => Promise<string>
+  private readonly executeBundle: (code: string, url: string) => void
+
+  /**
+   * Build the module system over the parsed boot rows.
+   * @param options - module rows, module-table staticModules, fetch/execute seams.
+   */
+  constructor(options: ClientModuleSystemOptions) {
+    this.seed = new Map(Object.entries(options.staticModules))
+    this.fetchBundle = options.fetchBundle ?? defaultFetchBundle
+    this.executeBundle = options.executeBundle ?? defaultExecuteBundle
+
+    for (const row of options.modules) {
+      if (this.graphRows.has(row.id)) throw new Error(`client-modules: duplicate graph entry "${row.id}"`)
+      this.graphRows.set(row.id, row)
+    }
+
+    const win = globalThis as DshWindow
+    if (win.__ModuleLoader__ !== undefined) throw new Error('client-modules: window.__ModuleLoader__ already installed (double boot?)')
+    win.__ModuleLoader__ = {
+      load: (handoff: ClientPluginHandoff): void => {
+        // Registration is keyed by the handoff id; a duplicate means a bundle
+        // executed twice without an invalidate — always a bug, always loud.
+        if (this.factories.has(handoff.id)) throw new Error(`client-modules: duplicate factory registration for "${handoff.id}" (bundle executed twice without invalidate?)`)
+        // A fetched row's bundle must register the id its row names — a
+        // mis-stamped bundle registering under another entry's identity
+        // would let that entry silently materialize foreign exports.
+        if (this.executingId !== '' && handoff.id !== this.executingId) {
+          throw new Error(`client-modules: bundle ${this.executingUrl} registered "${handoff.id}" while arriving for "${this.executingId}" (mis-stamped bundle id)`)
+        }
+        this.factories.set(handoff.id, { factory: handoff.factory, url: this.executingUrl })
+      },
+    }
+  }
+
+  /** Fetch + execute one graph row so its factory is registered (idempotent per in-flight arrival). */
+  private arrive(row: BootModuleRow): Promise<void> {
+    const { id, url } = row
+    const pending = this.pendingArrival.get(id)
+    if (pending !== undefined) return pending
+    if (this.factories.has(id)) return Promise.resolve()
+    const task = (async (): Promise<void> => {
+      const code = await this.fetchBundle(url)
+      this.executingUrl = url
+      this.executingId = id
+      try {
+        this.executeBundle(code, url)
+      } finally {
+        this.executingUrl = ''
+        this.executingId = ''
+      }
+      if (!this.factories.has(id)) {
+        throw new Error(`client-modules: bundle ${url} executed without registering "${id}" via __ModuleLoader__.load`)
+      }
+    })().finally(() => { this.pendingArrival.delete(id) })
+    this.pendingArrival.set(id, task)
+    return task
+  }
+
+  /** Materialize a registered factory (synchronous; memoized in loadCache). */
+  private materialize(id: string): ClientModuleRecord {
+    const existing = this.loadCache.get(id)
+    if (existing !== undefined) return existing
+    const registered = this.factories.get(id)
+    /* v8 ignore next -- callers check the factory branch before dispatching here. */
+    if (registered === undefined) throw new Error(`client-modules: no registered factory for "${id}"`)
+    if (this.materializing.has(id)) {
+      throw new Error(`client-modules: require cycle through "${id}" (factory-form CJS cannot deliver partial exports)`)
+    }
+    this.materializing.add(id)
+    try {
+      const edges = new Set<string>()
+      const surface = registered.factory(this.makeRequire(edges))
+      const record: ClientModuleRecord = { id, surface, styles: claimStyles(id), edges }
+      this.loadCache.set(id, record)
+      return record
+    } finally {
+      this.materializing.delete(id)
+    }
+  }
+
+  /**
+   * The synchronous require answered to factories: seed → static → memoized
+   * record → registered factory (recursive materialization — this is what
+   * makes load order self-resolving). Fetching is async and therefore
+   * unreachable from here; an unregistered plugin specifier is loud (and a
+   * cross-plugin value import is already a build error upstream).
+   */
+  private makeRequire(edges: Set<string>): (spec: string) => unknown {
+    return (spec: string): unknown => {
+      edges.add(spec)
+      if (this.seed.has(spec)) return this.seed.get(spec)
+      if (this.statics.has(spec)) return this.statics.get(spec)
+      const id = stripClientSuffix(spec)
+      const record = this.loadCache.get(id)
+      if (record !== undefined) return record.surface
+      if (this.factories.has(id)) return this.materialize(id).surface
+      throw new Error(
+        `client-modules: require("${spec}") missed the module table — not a platform seed word, not a shell-own module, `
+        + 'and no registered factory (a build-time externals drift, or a forbidden cross-plugin value import)',
+      )
+    }
+  }
+
+  async import(specifier: string): Promise<unknown> {
+    if (this.seed.has(specifier)) return this.seed.get(specifier)
+    const existing = this.loadCache.get(specifier)
+    if (existing !== undefined) return existing.surface
+    if (this.statics.has(specifier)) {
+      const surface = this.statics.get(specifier)
+      this.loadCache.set(specifier, { id: specifier, surface, styles: [], edges: new Set() })
+      return surface
+    }
+    if (!this.factories.has(specifier)) {
+      const row = this.graphRows.get(specifier)
+      if (row === undefined) {
+        throw new Error(
+          `client-modules: cannot resolve "${specifier}" — not a seed word, not a shell-own module, `
+          + 'and not a row in the boot graph (the runtime mirror of the bundle purity gate)',
+        )
+      }
+      await this.arrive(row)
+    }
+    return this.materialize(specifier).surface
+  }
+
+  registerStatic(id: string, module: unknown): void {
+    if (this.statics.has(id)) throw new Error(`client-modules: shell-own module "${id}" registered twice`)
+    this.statics.set(id, module)
+  }
+
+  async prefetch(id: string): Promise<void> {
+    if (this.statics.has(id)) return
+    const row = this.graphRows.get(id)
+    if (row === undefined) throw new Error(`client-modules: prefetch("${id}") — not a graph entry`)
+    await this.arrive(row)
+  }
+
+  invalidate(id: string): void {
+    this.factories.delete(id)
+    this.loadCache.delete(id)
+  }
+}

packages/client/modules/src/index.ts

@@ -0,0 +1,393 @@
+/**
+ * Node half of the client module system (dshClient dual-face package): scans
+ * the host Loader's entries for `dshClient` packages, composes the
+ * `window.__DSH_BOOT__` entry graph (wire single source: {@link WebBootEntry}
+ * in `./client/manifest.ts`), serves `/plugins/<id>/client.js`, taps the
+ * index render to inject the boot manifest, and provides the
+ * `clientModuleHost` service (the HMR node half's registration/notification
+ * face).
+ *
+ * Scanning is incremental per package — there is no full-rescan code path.
+ * Every cordis `internal/plugin` emission (fiber construction/disposal) marks
+ * the fiber's entry name dirty; a microtask flush reconciles each dirty name
+ * against the live loader entries. The activation pass seeds the same dirty
+ * set with all current entries and flushes synchronously, so first scan and
+ * steady state share one implementation. Package metadata (including the
+ * negative "not a client package" verdict) is cached per name and never
+ * expires — plugin-set changes take effect on restart per the config-source
+ * ruling; bundle content changes reach the graph only through
+ * {@link ClientModuleHostService.rebuilt}.
+ * @module @deepseek-ai/dsh-client-modules
+ */
+
+import { createHash } from 'node:crypto'
+import { readFileSync } from 'node:fs'
+import { readFile } from 'node:fs/promises'
+import type { IncomingMessage, ServerResponse } from 'node:http'
+import { createRequire } from 'node:module'
+import { dirname, join } from 'node:path'
+import { Service } from 'cordis'
+import type { Context } from 'cordis'
+import type {} from '@cordisjs/plugin-loader'
+import type {} from '@deepseek-ai/dsh-host-webserver'
+import type { WebBootEntry, WebBootGraph } from './client/manifest.ts'
+
+export type {
+  BootManifest, BootModuleRow, BootPluginRow, WebBootEntry, WebBootGraph,
+} from './client/manifest.ts'
+
+declare module 'cordis' {
+  interface Context {
+    /** The web plugin table (provided by the client-modules node half). */
+    clientModuleHost: ClientModuleHostService
+  }
+}
+
+/** package.json `dshClient` declaration shape (file boundary — validated field by field). */
+interface DshClientDeclaration {
+  inject?: string[]
+  platform: string
+  /** Boot phase-one prefetch mark; absent means lazy (fetched on demand). */
+  immediately?: boolean
+}
+
+/** Resolved package metadata for one dshClient package (cached per name, never expires). */
+interface PkgMeta {
+  clientPath: string
+  inject?: string[]
+  immediately: boolean
+}
+
+/** One composed table row: the wire entry plus its bundle path. */
+interface WebPluginRecord {
+  entry: WebBootEntry
+  clientPath: string
+}
+
+/** Narrow an unknown parsed JSON value to the dshClient declaration, throwing on malformed fields. */
+function parseDshClient(pkgName: string, value: unknown): DshClientDeclaration | undefined {
+  if (value === undefined) return undefined
+  if (typeof value !== 'object' || value === null) {
+    throw new Error(`client-modules: ${pkgName} has a non-object dshClient declaration`)
+  }
+  const decl = value as Record<string, unknown>
+  if (typeof decl.platform !== 'string') {
+    throw new Error(`client-modules: ${pkgName} dshClient.platform must be a string`)
+  }
+  if (decl.inject !== undefined && (!Array.isArray(decl.inject) || decl.inject.some(i => typeof i !== 'string'))) {
+    throw new Error(`client-modules: ${pkgName} dshClient.inject must be a string array`)
+  }
+  if (decl.immediately !== undefined && typeof decl.immediately !== 'boolean') {
+    throw new Error(`client-modules: ${pkgName} dshClient.immediately must be a boolean`)
+  }
+  return {
+    platform: decl.platform,
+    ...(decl.inject !== undefined ? { inject: decl.inject as string[] } : {}),
+    ...(decl.immediately !== undefined ? { immediately: decl.immediately } : {}),
+  }
+}
+
+/** Resolve `exports["./client"]` to a relative path, accepting the string and one-level conditional forms. */
+function clientExportOf(pkgName: string, exportsField: unknown): string | undefined {
+  if (typeof exportsField !== 'object' || exportsField === null) return undefined
+  const client = (exportsField as Record<string, unknown>)['./client']
+  if (client === undefined) return undefined
+  if (typeof client === 'string') return client
+  if (typeof client === 'object' && client !== null) {
+    const fallback = (client as Record<string, unknown>).default
+    if (typeof fallback === 'string') return fallback
+  }
+  throw new Error(`client-modules: ${pkgName} exports["./client"] has an unsupported shape`)
+}
+
+/** sha1 content hash shortened to 12 hex chars (bundle rev / graph rev). */
+function shortHash(input: string | Buffer): string {
+  return createHash('sha1').update(input).digest('hex').slice(0, 12)
+}
+
+/** Graph row for one bundle rev (url carries the rev as its cache-busting query). */
+function graphRow(id: string, rev: string, injectEdges: string[] | undefined, immediately: boolean): WebBootEntry {
+  return {
+    id,
+    url: `/plugins/${id}/client.js?rev=${rev}`,
+    rev,
+    ...(injectEdges !== undefined ? { inject: injectEdges } : {}),
+    ...(immediately ? { immediately: true } : {}),
+  }
+}
+
+/**
+ * Inject the boot entry graph into index.html: `window.__DSH_BOOT__` as the
+ * first script in <head> (before the shell bundle reads it). `<` is escaped in
+ * the JSON so plugin-controlled strings cannot break out of the script element.
+ * @param html - the index.html source.
+ * @param graph - the composed entry graph.
+ * @returns the html with the graph script injected.
+ */
+export function injectBootManifest(html: string, graph: WebBootGraph): string {
+  const json = JSON.stringify(graph).replaceAll('<', '\\u003c')
+  const script = `<script>window.__DSH_BOOT__ = ${json}</script>`
+  const head = html.indexOf('<head>')
+  if (head !== -1) return `${html.slice(0, head + 6)}${script}${html.slice(head + 6)}`
+  // Headless fixture pages may lack <head>; prepending keeps the read-before-shell ordering.
+  return `${script}${html}`
+}
+
+/**
+ * The web plugin table service: incremental dshClient scan + wire composition
+ * + bundle route + index tap. Construction runs the activation scan
+ * synchronously — a malformed declaration or missing bundle among the
+ * already-loaded entries aggregates into one loud throw (FAILED fiber; the
+ * boot sweep reports it).
+ */
+export class ClientModuleHostService extends Service {
+  static inject = ['httpServer', 'loader']
+
+  private readonly table = new Map<string, WebPluginRecord>()
+  // Negative verdicts (unresolvable specifier — builtins like cordis:include,
+  // subpath rows — or a package without a web dshClient declaration) are
+  // cached as null and never expire: plugin-set changes take effect on restart.
+  private readonly pkgMeta = new Map<string, PkgMeta | null>()
+  private readonly rebuildListeners = new Set<(id: string, rev: string) => void>()
+  private readonly graphListeners = new Set<() => void>()
+  private readonly dirty = new Set<string>()
+  private readonly resolvePkgJson: (spec: string) => string
+  private flushQueued = false
+  private composed: WebBootGraph
+
+  /**
+   * Build the service: subscribe, seed, and run the activation flush.
+   * @param ctx - plugin context carrying httpServer and loader.
+   */
+  constructor(ctx: Context) {
+    super(ctx, 'clientModuleHost')
+    // Resolution anchor: the config tree's baseUrl (the cordis.yml directory,
+    // whose package declares every composed plugin as a dependency). The
+    // modules package's own URL would miss sibling packages under pnpm's
+    // isolated node_modules.
+    if (ctx.baseUrl === undefined) {
+      throw new Error('client-modules: ctx.baseUrl is unset — the node half needs the config-tree anchor to resolve plugin packages')
+    }
+    const require = createRequire(ctx.baseUrl)
+    this.resolvePkgJson = spec => require.resolve(`${spec}/package.json`)
+
+    // Subscribe before seeding so a fiber arriving mid-activation lands in the
+    // same dirty set (Set idempotence makes the overlap harmless). An entry-less
+    // fiber is a child plugin or a manual mount — never a loader row; O(1) drop.
+    ctx.on('internal/plugin', (fiber) => {
+      const entryName = fiber.entry?.options.name
+      if (entryName === undefined) return
+      this.dirty.add(entryName)
+      if (this.flushQueued) return
+      this.flushQueued = true
+      queueMicrotask(() => {
+        this.flushQueued = false
+        this.flush((err) => { ctx.logger.warn(err) })
+      })
+    })
+
+    // Activation pass: the initial scan IS the incremental path over the
+    // current entries, flushed synchronously (nothing async between subscribe,
+    // seed, and flush).
+    for (const entry of ctx.loader.entries()) this.dirty.add(entry.options.name)
+    this.composed = this.compose()
+    const failures: Error[] = []
+    this.flush(err => failures.push(err))
+    if (failures.length > 0) {
+      throw new AggregateError(
+        failures,
+        `client-modules: ${String(failures.length)} client package(s) failed to compose:\n${failures.map(e => `  - ${e.message}`).join('\n')}`,
+      )
+    }
+
+    ctx.effect(
+      () => ctx.httpServer.register({ kind: 'prefix', path: '/plugins', handler: this.serveBundle }),
+      'client-modules: bundle route',
+    )
+    ctx.effect(
+      () => ctx.httpServer.tapIndex(html => injectBootManifest(html, this.composed)),
+      'client-modules: boot manifest injection',
+    )
+  }
+
+  /**
+   * Current composed entry graph (stable object between changes).
+   * @returns the graph served as `window.__DSH_BOOT__`.
+   */
+  graph(): WebBootGraph {
+    return this.composed
+  }
+
+  /**
+   * Absolute path of an entry's client bundle.
+   * @param id - entry id (package name).
+   * @returns the path, or undefined for an unknown id.
+   */
+  clientPath(id: string): string | undefined {
+    return this.table.get(id)?.clientPath
+  }
+
+  /**
+   * Re-hash one bundle (the HMR watch's registration hook — the only entry
+   * point through which bundle content changes reach the graph).
+   * @param id - entry id (package name).
+   * @returns the new rev, or undefined for an unknown id.
+   */
+  rebuilt(id: string): string | undefined {
+    const record = this.table.get(id)
+    if (record === undefined) return undefined
+    const rev = shortHash(readFileSync(record.clientPath))
+    if (rev === record.entry.rev) return rev
+    record.entry = graphRow(id, rev, record.entry.inject, record.entry.immediately === true)
+    this.composed = this.compose()
+    for (const notify of this.rebuildListeners) {
+      // Containment: rebuilt() runs inside the HMR watch callback — a
+      // throwing subscriber must not kill the poll or skip later subscribers.
+      try {
+        notify(id, rev)
+      } catch (error) {
+        this.ctx.logger.error(error)
+      }
+    }
+    this.notifyGraphChanged()
+    return rev
+  }
+
+  /**
+   * Subscribe to bundle rebuilds; fires only when the re-hash changed the rev.
+   * @param listener - receives the entry id and its new bundle rev.
+   * @returns the unsubscriber.
+   */
+  onRebuilt(listener: (id: string, rev: string) => void): () => void {
+    this.rebuildListeners.add(listener)
+    return () => { this.rebuildListeners.delete(listener) }
+  }
+
+  /**
+   * Fires after any flush that recomposed the graph (row added/removed, or a
+   * rebuilt rev change). Pull model: listeners re-read {@link graph}.
+   * @param listener - notified with no payload.
+   * @returns the unsubscriber.
+   */
+  onGraphChanged(listener: () => void): () => void {
+    this.graphListeners.add(listener)
+    return () => { this.graphListeners.delete(listener) }
+  }
+
+  private compose(): WebBootGraph {
+    const entries = [...this.table.values()].map(record => record.entry)
+    return { rev: shortHash(JSON.stringify(entries)), entries }
+  }
+
+  private notifyGraphChanged(): void {
+    for (const listener of this.graphListeners) {
+      // A throwing subscriber must not skip later subscribers (or escape into
+      // whatever triggered the flush — possibly an fs.watchFile callback).
+      try {
+        listener()
+      } catch (error) {
+        this.ctx.logger.error(error)
+      }
+    }
+  }
+
+  private resolveMeta(pkgName: string): PkgMeta | null {
+    const cached = this.pkgMeta.get(pkgName)
+    if (cached !== undefined) return cached
+    let pkgPath: string
+    try {
+      pkgPath = this.resolvePkgJson(pkgName)
+    } catch {
+      // Not a resolvable package root: loader builtins (cordis:include) and
+      // subpath entries (…/gateway) land here — permanently not a client row.
+      this.pkgMeta.set(pkgName, null)
+      return null
+    }
+    const pkg = JSON.parse(readFileSync(pkgPath, 'utf8')) as Record<string, unknown>
+    const decl = parseDshClient(pkgName, pkg.dshClient)
+    if (decl === undefined || decl.platform !== 'web') {
+      this.pkgMeta.set(pkgName, null)
+      return null
+    }
+    const clientRel = clientExportOf(pkgName, pkg.exports)
+    if (clientRel === undefined) {
+      throw new Error(`client-modules: ${pkgName} declares dshClient but exports no "./client" bundle`)
+    }
+    const meta: PkgMeta = {
+      clientPath: join(dirname(pkgPath), clientRel),
+      ...(decl.inject !== undefined ? { inject: decl.inject } : {}),
+      immediately: decl.immediately === true,
+    }
+    this.pkgMeta.set(pkgName, meta)
+    return meta
+  }
+
+  /** Reconcile one entry name against the live loader entries. @returns whether the table changed. */
+  private processOne(entryName: string): boolean {
+    let qualifies = false
+    for (const entry of this.ctx.loader.entries()) {
+      if (entry.options.name === entryName && entry.fiber !== undefined && !entry.disabled) {
+        qualifies = true
+        break
+      }
+    }
+    if (!qualifies) return this.table.delete(entryName)
+    if (this.table.has(entryName)) return false
+    const meta = this.resolveMeta(entryName)
+    if (meta === null) return false
+    // The rev rides the row from here on: a fiber restart reuses the row (and
+    // its rev) untouched; only rebuilt() re-reads the bundle.
+    const rev = shortHash(readFileSync(meta.clientPath))
+    this.table.set(entryName, { entry: graphRow(entryName, rev, meta.inject, meta.immediately), clientPath: meta.clientPath })
+    return true
+  }
+
+  private flush(onError: (err: Error) => void): void {
+    let changed = false
+    for (const entryName of [...this.dirty]) {
+      this.dirty.delete(entryName)
+      try {
+        if (this.processOne(entryName)) changed = true
+      } catch (error) {
+        // Steady state: one broken package must not poison the others; the
+        // activation pass aggregates these into a loud throw instead.
+        onError(error instanceof Error ? error : new Error(String(error)))
+      }
+    }
+    if (changed) {
+      this.composed = this.compose()
+      this.notifyGraphChanged()
+    }
+  }
+
+  private readonly serveBundle = async (req: IncomingMessage, res: ServerResponse): Promise<void> => {
+    if (req.method !== 'GET' && req.method !== 'HEAD') {
+      res.writeHead(405)
+      res.end()
+      return
+    }
+    /* v8 ignore next -- `?? '/'` arm: node:http always sets url on server requests. */
+    const pathname = decodeURIComponent(new URL(req.url ?? '/', 'http://x').pathname)
+    // The id may contain a scope slash. Anything else under /plugins (including
+    // /plugins/events when the HMR row is absent) is an unknown resource.
+    const path = pathname.startsWith('/plugins/') && pathname.endsWith('/client.js')
+      ? this.clientPath(pathname.slice('/plugins/'.length, -'/client.js'.length))
+      : undefined
+    if (path === undefined) {
+      res.writeHead(404)
+      res.end()
+      return
+    }
+    try {
+      const body = await readFile(path)
+      res.writeHead(200, { 'content-type': 'text/javascript; charset=utf-8', 'cache-control': 'no-cache' })
+      res.end(body)
+    } catch {
+      // Registered but unreadable (bundle not built yet): loud 404 beats a silent SPA-fallback HTML page.
+      res.writeHead(404)
+      res.end()
+    }
+  }
+}
+
+export default ClientModuleHostService

packages/client/modules/src/invariant.ts

@@ -0,0 +1,45 @@
+/**
+ * Package-owned invariant companion for `@deepseek-ai/dsh-client-modules`.
+ * @module @deepseek-ai/dsh-client-modules/invariant
+ */
+
+/* jscpd:ignore-start */
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-client-modules'
+
+/** Cordis companion plugin name. */
+export const name = 'client-modules-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/**
+ * Owned relation: the node half's boot entry graph must stay self-consistent
+ * — every row must resolve a clientPath under the same id (the
+ * /plugins/<id>/client.js URL it advertises would otherwise 404 on a browser
+ * that just received the graph). Checked on every scan trigger (cordis
+ * 'internal/plugin'): graph() and clientPath() read the same table object,
+ * so the relation holds at any instant — no need to wait out the node half's
+ * own microtask-debounced flush.
+ */
+const install: InvariantInstaller = (ctx, fail) => {
+  ctx.on('internal/plugin', () => {
+    const host = ctx.get('clientModuleHost')
+    if (host === undefined) return // browser side / host without the node half: nothing to audit
+    for (const row of host.graph().entries) {
+      if (host.clientPath(row.id) === undefined) {
+        fail(`web plugin graph row "${row.id}" advertises ${row.url} but resolves no client bundle path — the served __DSH_BOOT__ would 404 on fetch`)
+      }
+    }
+  }, { global: true })
+}
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
+/* jscpd:ignore-end */

packages/client/modules/tests/loader.spec.ts

@@ -0,0 +1,301 @@
+// @vitest-environment jsdom
+/**
+ * ClientModuleSystem behavior: lazy CJS arrival (bundle execution only
+ * registers the factory), materialization on first import/require with
+ * memoization and recursive self-sequencing, the resolution branch order,
+ * shared in-flight arrival, invalidate-refetch (HMR), style claiming, the
+ * default transport seams, and the loud failure modes (duplicate
+ * registration, cycles, table misses, double boot).
+ */
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import {
+  ClientModuleSystem,
+  type BootModuleRow, type ClientModuleLoader, type ClientPluginHandoff, type DshWindow,
+} from '../src/client/index.ts'
+
+const win = globalThis as DshWindow
+
+type Factory = ClientPluginHandoff['factory']
+
+afterEach(() => {
+  vi.unstubAllGlobals()
+  delete win.__ModuleLoader__
+  delete (document as unknown as Record<string, unknown>).__realmBridge
+  for (const el of document.querySelectorAll('style, script')) el.remove()
+})
+
+const row = (id: string): BootModuleRow => ({ id, url: `/plugins/${id}/client.js?rev=0`, rev: '0' })
+
+interface Bench {
+  loader: ClientModuleLoader
+  fetched: string[]
+  gates: Map<string, () => void>
+}
+
+/**
+ * Loader over scripted bundles: fetch resolves to the row url (optionally
+ * gated on a release callback); execute registers the scripted factory
+ * through the window sink (`null` scripts a bundle that never calls load).
+ */
+function bench(
+  entries: BootModuleRow[],
+  bundles: Record<string, Factory | null> = {},
+  opts: { seed?: Record<string, unknown>; gated?: string[] } = {},
+): Bench {
+  const fetched: string[] = []
+  const gates = new Map<string, () => void>()
+  const loader = new ClientModuleSystem({
+    modules: entries,
+    staticModules: opts.seed ?? {},
+    fetchBundle: (url) => {
+      fetched.push(url)
+      if (opts.gated?.includes(url) === true) {
+        return new Promise((resolve) => { gates.set(url, () => { resolve(url) }) })
+      }
+      return Promise.resolve(url)
+    },
+    executeBundle: (code) => {
+      const id = /\/plugins\/(.+)\/client\.js/.exec(code)?.[1]
+      const factory = id === undefined ? undefined : bundles[id]
+      if (factory == null || id === undefined) return
+      win.__ModuleLoader__?.load({ id, factory })
+    },
+  })
+  return { loader, fetched, gates }
+}
+
+describe('lazy CJS arrival', () => {
+  it('prefetch fetches and executes but does not run the factory', async () => {
+    const ran: string[] = []
+    const b = bench([row('a')], { a: () => { ran.push('a'); return {} } })
+    await b.loader.prefetch('a')
+    expect(b.fetched).toEqual(['/plugins/a/client.js?rev=0'])
+    expect(ran).toEqual([])
+    expect(b.loader.loadCache.size).toBe(0)
+  })
+
+  it('import materializes once and memoizes the export surface', async () => {
+    const ran: string[] = []
+    const b = bench([row('a')], { a: () => { ran.push('a'); return { marker: 'a' } } })
+    const first = await b.loader.import('a', '', {})
+    const second = await b.loader.import('a', '', {})
+    expect(first).toBe(second)
+    expect((first as { marker: string }).marker).toBe('a')
+    expect(ran).toEqual(['a'])
+    expect(b.loader.loadCache.get('a')?.id).toBe('a')
+  })
+
+  it('import without prefetch fetches, executes, and materializes in one call', async () => {
+    const b = bench([row('a')], { a: () => ({ marker: 'direct' }) })
+    const surface = await b.loader.import('a', '', {})
+    expect((surface as { marker: string }).marker).toBe('direct')
+    expect(b.fetched).toHaveLength(1)
+  })
+
+  it('concurrent callers share one in-flight arrival and materialize once', async () => {
+    const ran: string[] = []
+    const url = '/plugins/a/client.js?rev=0'
+    const b = bench([row('a')], { a: () => { ran.push('a'); return { marker: 'a' } } }, { gated: [url] })
+    const first = b.loader.import('a', '', {})
+    const second = b.loader.import('a', '', {})
+    const third = b.loader.prefetch('a')
+    b.gates.get(url)?.()
+    const [s1, s2] = await Promise.all([first, second, third])
+    expect(s1).toBe(s2)
+    expect(b.fetched).toEqual([url])
+    expect(ran).toEqual(['a'])
+  })
+
+  it('prefetch after registration is a no-op without invalidate', async () => {
+    const b = bench([row('a')], { a: () => ({}) })
+    await b.loader.prefetch('a')
+    await b.loader.prefetch('a')
+    expect(b.fetched).toHaveLength(1)
+  })
+})
+
+describe('require resolution', () => {
+  it('a factory requiring a registered-but-unmaterialized module materializes it recursively', async () => {
+    const order: string[] = []
+    const b = bench([row('a'), row('b')], {
+      a: (req) => {
+        order.push('a')
+        const dep = req('b/client') as { helper: string }
+        return { got: dep.helper }
+      },
+      b: () => { order.push('b'); return { helper: 'from-b' } },
+    })
+    await b.loader.prefetch('a')
+    await b.loader.prefetch('b')
+    const surface = await b.loader.import('a', '', {})
+    expect((surface as { got: string }).got).toBe('from-b')
+    expect(order).toEqual(['a', 'b'])
+    expect(b.loader.loadCache.get('a')?.edges.has('b/client')).toBe(true)
+    expect(b.loader.loadCache.has('b')).toBe(true)
+  })
+
+  it('require prefers the platform seed word over the module table', async () => {
+    const react = { marker: 'react' }
+    const b = bench([row('a')], {
+      a: req => ({ dep: req('react') }),
+    }, { seed: { react } })
+    const surface = await b.loader.import('a', '', {})
+    expect((surface as { dep: unknown }).dep).toBe(react)
+    expect(await b.loader.import('react', '', {})).toBe(react)
+    expect(b.loader.loadCache.has('react')).toBe(false)
+  })
+
+  it('require answers an already-materialized module from the cache', async () => {
+    let built = 0
+    const b = bench([row('a'), row('c')], {
+      a: req => ({ dep: req('c') }),
+      c: () => { built += 1; return { marker: 'c' } },
+    })
+    const c = await b.loader.import('c', '', {})
+    const a = await b.loader.import('a', '', {})
+    expect((a as { dep: unknown }).dep).toBe(c)
+    expect(built).toBe(1)
+  })
+
+  it('a require that misses the module table is loud', async () => {
+    const b = bench([row('a')], { a: req => ({ dep: req('ghost') }) })
+    await expect(b.loader.import('a', '', {})).rejects.toThrow('require("ghost") missed the module table')
+  })
+
+  it('a require cycle is fatal', async () => {
+    const b = bench([row('a'), row('b')], {
+      a: req => ({ dep: req('b') }),
+      b: req => ({ dep: req('a') }),
+    })
+    await b.loader.prefetch('b')
+    await expect(b.loader.import('a', '', {})).rejects.toThrow('require cycle through "a"')
+  })
+})
+
+describe('static registry', () => {
+  it('serves shell-own modules to import and require without any fetch', async () => {
+    const shell = { marker: 'app-shell' }
+    const b = bench([row('a')], {
+      a: req => ({ dep: req('app-shell') }),
+    })
+    b.loader.registerStatic('app-shell', shell)
+    await b.loader.prefetch('app-shell')
+    expect(await b.loader.import('app-shell', '', {})).toBe(shell)
+    expect(b.loader.loadCache.get('app-shell')?.styles).toEqual([])
+    expect((await b.loader.import('a', '', {}) as { dep: unknown }).dep).toBe(shell)
+    expect(b.fetched).toEqual(['/plugins/a/client.js?rev=0'])
+  })
+
+  it('duplicate static registration is loud', () => {
+    const b = bench([])
+    b.loader.registerStatic('app-shell', {})
+    expect(() => { b.loader.registerStatic('app-shell', {}) }).toThrow('registered twice')
+  })
+})
+
+describe('failure modes', () => {
+  it('duplicate factory registration is loud', () => {
+    bench([])
+    win.__ModuleLoader__?.load({ id: 'x', factory: () => ({}) })
+    expect(() => win.__ModuleLoader__?.load({ id: 'x', factory: () => ({}) }))
+      .toThrow('duplicate factory registration for "x"')
+  })
+
+  it('a bundle that never registers its id is loud', async () => {
+    const b = bench([row('a')], { a: null })
+    await expect(b.loader.import('a', '', {})).rejects.toThrow('without registering "a"')
+  })
+
+  it('an unknown import specifier is loud', async () => {
+    const b = bench([])
+    await expect(b.loader.import('nope', '', {})).rejects.toThrow('cannot resolve "nope"')
+  })
+
+  it('an unknown prefetch id is loud', async () => {
+    const b = bench([])
+    await expect(b.loader.prefetch('nope')).rejects.toThrow('prefetch("nope") — not a graph entry')
+  })
+
+  it('a duplicate graph entry is loud at construction', () => {
+    expect(() => bench([row('a'), row('a')])).toThrow('duplicate graph entry "a"')
+  })
+
+  it('double boot is loud', () => {
+    bench([])
+    expect(() => new ClientModuleSystem({ modules: [], staticModules: {} }))
+      .toThrow('already installed (double boot?)')
+  })
+})
+
+describe('HMR reset', () => {
+  it('invalidate drops the factory and record so the module refetches and re-registers', async () => {
+    let generation = 0
+    const b = bench([row('a')], { a: () => ({ generation: ++generation }) })
+    const first = await b.loader.import('a', '', {})
+    b.loader.invalidate('a')
+    expect(b.loader.loadCache.has('a')).toBe(false)
+    await b.loader.prefetch('a')
+    const second = await b.loader.import('a', '', {})
+    expect(b.fetched).toHaveLength(2)
+    expect((first as { generation: number }).generation).toBe(1)
+    expect((second as { generation: number }).generation).toBe(2)
+  })
+})
+
+describe('style claiming', () => {
+  it('claims untagged style tags for the materializing plugin and inventories owned css ids', async () => {
+    const foreign = document.createElement('style')
+    foreign.setAttribute('data-plugin', 'other')
+    document.head.appendChild(foreign)
+    const b = bench([row('a')], {
+      a: () => {
+        document.head.appendChild(document.createElement('style'))
+        const tagged = document.createElement('style')
+        tagged.setAttribute('data-plugin', 'a')
+        tagged.setAttribute('data-plugin-css', 'sheet-1')
+        document.head.appendChild(tagged)
+        return {}
+      },
+    })
+    await b.loader.import('a', '', {})
+    expect(b.loader.loadCache.get('a')?.styles).toEqual(['a', 'sheet-1'])
+    expect(document.querySelectorAll('style[data-plugin="a"]')).toHaveLength(2)
+    expect(foreign.getAttribute('data-plugin')).toBe('other')
+  })
+
+  it('materialization without a document skips the style inventory', async () => {
+    const b = bench([row('a')], { a: () => ({}) })
+    vi.stubGlobal('document', undefined)
+    try {
+      await b.loader.import('a', '', {})
+    } finally {
+      vi.unstubAllGlobals()
+    }
+    expect(b.loader.loadCache.get('a')?.styles).toEqual([])
+  })
+})
+
+describe('default transport seams', () => {
+  it('fetches same-origin and executes through an inline script tag', async () => {
+    // In a browser the loader's globalThis IS the page window; vitest's jsdom
+    // evaluates <script> in a separate realm that shares only the document,
+    // so the fixture bundle restores the sink from a document bridge before
+    // using the normal calling convention.
+    const code = 'window.__ModuleLoader__ = document.__realmBridge;\n'
+      + 'window.__ModuleLoader__.load({ id: "dee", factory: function () { return { marker: "via-script" } } })'
+    vi.stubGlobal('fetch', async () => ({ ok: true, text: async () => code }))
+    const loader: ClientModuleLoader = new ClientModuleSystem({ modules: [row('dee')], staticModules: {} })
+    ;(document as unknown as Record<string, unknown>).__realmBridge = win.__ModuleLoader__
+    const surface = await loader.import('dee', '', {})
+    expect((surface as { marker: string }).marker).toBe('via-script')
+    // The script node is removed right after its synchronous execution —
+    // repeated HMR rebuilds must not accumulate dead script nodes.
+    expect([...document.querySelectorAll('script')]).toEqual([])
+  })
+
+  it('a non-ok bundle response is loud with the status', async () => {
+    vi.stubGlobal('fetch', async () => ({ ok: false, status: 404 }))
+    const loader = new ClientModuleSystem({ modules: [row('dee')], staticModules: {} })
+    await expect(loader.prefetch('dee')).rejects.toThrow('answered 404')
+  })
+})

packages/client/modules/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types",
+    "lib": ["ES2024", "DOM", "DOM.Iterable"],
+    "types": ["node"]
+  },
+  "include": ["src"],
+  "references": [
+    { "path": "../../../vendor/cordis" },
+    { "path": "../../../vendor/loader" },
+    { "path": "../../host/webserver" },
+    { "path": "../../support/invariants" }
+  ]
+}

packages/client/modules/tsdown.config.ts

@@ -0,0 +1,3 @@
+import { clientBundle } from '../tsdown.client.ts'
+
+export default clientBundle('@deepseek-ai/dsh-client-modules', ['lib/types/index.js', 'lib/types/invariant.js'])

packages/client/runtime/README.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write packages/client/runtime/README.md
+README.md: 25eb60e2c95059ae918669c9f5169b6b8e9c6816
+README.zh.md: e3085f91750503aeaffda41d86c40c62943b4ba9

packages/client/runtime/README.md

@@ -1,18 +1,43 @@
 # @deepseek-ai/dsh-client-runtime
 
-Client cordis boot + core services: SlotsService (Service wrapper over SlotCore + 'slots/changed' bridge), SessionsService (list store projection, scope tree, bindings, ancestry), Session object layer, ClientLoader (`./loader` subpath, statically held by the shell). Contract: api-contracts v3 §4.
+English | [中文](README.zh.md)
+
+Client cordis boot and React-free object services: SlotsService wraps SlotCore and supplies renderer data sources; SessionsService owns Session objects, list/scope/history state; WorkspacesService depends on SessionsService and owns Workspace objects, list/actions, default-target derivation, and the New Session blank-reuse entry (`connectWorkspace`). The runtime fans the shared Host stream into both managers. Client sessions are always Host-born (Session+Agent+cwd in one `session.create`); the client holds no pre-entity session state — a session's Agent scope (the client mirror of host dsh-scope, keyed by the shared agent/session id) is born when its row enters the list mirror and dies with the prune. Contract: api-contracts v3 §4. Each `Session` holds a generic `ProjectionValueStore` seeded from the history-tail `projections` block and updated by `session/projection` frames under higher-seq-wins; domain keys (including `todos`) are read via `projections.faceOf` / `useProjection`, not via `ConversationSnapshot`.
+
+## Workspace and Session lists
+
+Workspace and Session lists have independent monotone `pending` → `ready` baseline phases and separate refresh activity/error state. Incremental upsert/removal frames and unary mutation echoes arriving during a list request replay over its response. The first successful baseline establishes Host order; later refreshes update rows and membership without changing the relative order of identities already shown. Removed Workspace ids retain process-local tombstones so late changed frames cannot resurrect them; reconnect still takes `workspace.list` as the baseline. Workspace recency is derived only after both baselines are ready and never changes Workspace list order.
+
+`WorkspacesService.delete(workspaceId)` removes the registration from the client projection after the successful unary response; the matching `host/workspace-removed` frame is idempotent and synchronizes other tabs. Session state and the current Session selection are independent, so accounted Sessions immediately project under Ungrouped after their Workspace disappears.
+
+SlotsService gives the renderer separate bare observables for `useSessions` and `useWorkspaces`; web-react creates the hooks. Workspace business state does not enter `SessionListState` or an entry store.
+
+## New Session and the blank mirror
+
+`WorkspacesService.connectWorkspace(workspaceId)` resolves the session a New Session flow lands in: it reuses the workspace's existing blank session from the list mirror (`blank && cwd == workspace.path`) or calls `session.create({workspaceId})`, returning the session id for the caller to open. `SessionSummary.blank` mirrors the host's derived empty-log bit and only ever lowers on the client: seeded by `session.list` / the `host/session-added` frame, flipped false by the first ACCEPTED local `prompt()` (on the RPC success response — acceptance proves the user message is in the host log; a rejected first prompt keeps the session blank and reusable) and by any `running: true` status frame, re-aligned by every list re-pull. List surfaces hide blank rows; the store carries every row. `SessionsService.create` accepts an optional caller-preallocated SessionId and throws `SessionCreateError` (carrying `requestedSessionId`) on failure.
+
+## Code Mode sub-dispatch index
+
+`ConversationSnapshot.codeDispatches` groups a `run_code` call's sub-dispatches under their parent callId, in start order, using the native call-block shapes: a `tool/code-dispatch-start` event lands the `RunningToolCall` form (rows derive the running ring from the shape) and its `tool/code-dispatch` settlement replaces it in place with the `ToolResultNode` form, `callTime` carrying the paired start's time. A settle whose start fell outside the replay window appends directly with `callTime: null` (duration unknown — never a fabricated zero). Live mux frames and history replay build the identical index; sub-calls never join the surface `nodes` flow; per-parent array and map references are memo-stable across unrelated snapshot swaps.
+
+## Session title projection
+
+`SessionManager` retains the latest validated `session/title` control snapshot independently of list and session-instance arrival. Newer event seqs replace older snapshots, title timestamps contribute to list recency, and a subscription baseline discards any retained title beyond its `lastSeq` before the optional folded title arrives. Explicit session removal also clears the retained title. The client-facing `SessionSummary.title` is therefore only the actual durable title; `displayTitle` is always present and falls back through the cwd basename and session id. A cold persisted session keeps that fallback until opening or resuming it causes the host to fold and project its log-backed title.
+
+## Session model selection
+
+Each resident `Session` owns a `modelSelection` snapshot containing the current provider/model target, provider-grouped directory, provider-local failures, and the `idle`/`loading`/`ready`/`selecting`/`error` state. History establishes or refreshes the current target, opening a selector refreshes the directory, and selection failures preserve the last target and usable groups. Directory and selection operations share a monotonically increasing generation so an older response cannot overwrite a newer selection. A reconnect rebuild restores the target reported by the Host without replacing unchanged selection substructure.
 
 ## Model Experience
 
-None, as the client runtime hosts browser-side services and the session object layer; nothing here reaches a model request.
+None, as the session object layer selects the provider/model route used by a later Host request but adds no model-visible content.
 
 #### KV Cache effect
 
-None; this package neither assembles nor sends a provider request.
+Changing the target can change or invalidate provider-side cache reuse; this package does not alter the prompt prefix itself.
 
 ## Known Limitations and Deferred Work
 
 - **`loader.unload` is a stub (throws not-implemented)** — the full chain (fiber dispose → registration cascade → style removal) lands with the HMR project.
-- **Scope teardown is watch-approximated** — the most recently resolved binding stands in for "who is watching"; a removed-while-watched session's scope survives until the watch moves away, not until true observer count reaches zero.
+- **Scope teardown is stage-driven, single-occupant today** — the staged session follows `list.current` exactly (staging is the open signal: the event window opens ⟺ the session is on stage); a removed-while-staged session's scope survives frozen until the stage moves on, not until true observer count reaches zero. Resolution (`binding()`/`scope()`) is pure addressing, render-safe; the render layer reads the current bundle through the `currentProvideInfo` observable. The staged state can widen to a multi-pane list when concurrent panes land.
 - **Value imports of this package from plugin bundles must use the `/client` subpath** — the bare package name is not in the loader externals table and inlines a second module instance, whose private scope-tag Symbol never matches (the empty-state P0 postmortem).
-- **`SessionSummary.title` is a display projection** — the wire summary carries no title yet; the cwd basename stands in, then the raw id.

packages/client/runtime/README.zh.md

@@ -0,0 +1,43 @@
+# @deepseek-ai/dsh-client-runtime
+
+[English](README.md) | 中文
+
+客户端 cordis 启动与不依赖 React 的对象服务：SlotsService 包装 SlotCore 并提供 renderer 数据源；SessionsService 拥有 Session 对象、列表／scope／history 状态；WorkspacesService 依赖 SessionsService，拥有 Workspace 对象、列表／操作、默认目标派生，以及 New Session 空会话复用入口（`connectWorkspace`）。运行时把共享 Host 流分发给两个 manager。客户端 Session 一律由 Host 出生（一次 `session.create` 同瞬产出 Session+Agent+cwd）；客户端不持有任何实体化之前的会话状态——Agent scope（host dsh-scope 的客户端镜像，以 agent/session 共用 id 为键）在会话行进入列表镜像时出生，随 prune 死亡。契约：api-contracts v3 §4。每个 `Session` 持有一个通用的 `ProjectionValueStore`，由历史尾页的 `projections` 块播种，并经 `session/projection` 帧按 seq 高者胜更新；领域键（含 `todos`）经 `projections.faceOf`／`useProjection` 读取，不经 `ConversationSnapshot`。
+
+## Workspace 与 Session 列表
+
+Workspace 和 Session 列表各自具有单调的 `pending` → `ready` 基线阶段，也有各自的刷新活动／错误状态。列表请求期间到达的增量更新／移除帧与一元变更回显会在其响应之上回放。第一次成功的基线建立 Host 顺序；后续刷新更新行和成员关系，但不改变已经显示的标识之间的相对顺序。已移除的 Workspace id 会保留进程本地删除标记，避免延迟到达的 changed 帧将其复活；重连仍以 `workspace.list` 作为基线。Workspace 新近程度只在两条基线都 ready 后派生，且绝不改变 Workspace 列表顺序。
+
+`WorkspacesService.delete(workspaceId)` 在一元响应成功后从客户端投影中移除注册记录；对应的 `host/workspace-removed` 帧具有幂等性，并负责同步其他标签页。Session 状态与当前 Session selection 相互独立，因此 Workspace 消失后，其已记账的 Session 会立即投影到 Ungrouped 下。
+
+SlotsService 分别为 renderer 提供 `useSessions` 与 `useWorkspaces` 的裸 observable；web-react 创建 hook。Workspace 业务状态不会进入 `SessionListState` 或配置项 store。
+
+## New Session 与 blank 镜像
+
+`WorkspacesService.connectWorkspace(workspaceId)` 解析 New Session 流程最终落入的会话：先在列表镜像中复用该 workspace 的既有空会话（`blank && cwd == workspace.path`），未命中则调用 `session.create({workspaceId})`，返回会话 id 由调用方 open。`SessionSummary.blank` 镜像主机派生的空日志位，在客户端只降不升：由 `session.list`／`host/session-added` 帧播种，本地首次**受理成功**的 `prompt()`（RPC 成功响应时——受理即证明用户消息已入主机日志；首讯被拒则会话保持 blank、保持可复用）与任何 `running: true` 状态帧翻为 false，每次列表重拉重新对齐。列表表面隐藏 blank 行；store 保留全部行。`SessionsService.create` 接受可选的、由调用方预先分配的 SessionId，失败时抛出 `SessionCreateError`（携带 `requestedSessionId`）。
+
+## Code Mode 子调用索引
+
+`ConversationSnapshot.codeDispatches` 按父调用的 callId 和启动顺序，用原生调用块形状组织一个 `run_code` 调用的子调用：`tool/code-dispatch-start` 事件落成 `RunningToolCall` 形状（行组件从该形状推导运行中的转圈状态），其 `tool/code-dispatch` 完结事件原位替换为 `ToolResultNode` 形状，`callTime` 携带成对 start 事件的时间。start 落在回放窗口之外的完结事件则直接追加，`callTime: null`（耗时未知——绝不伪造零耗时）。live mux 帧与历史回放构建相同的索引；子调用永不进入 surface `nodes` 流；无关快照交换不会改变每个父调用对应的数组引用和映射引用，两者均保持 memo 稳定。
+
+## Session 标题投影
+
+`SessionManager` 独立于列表和 Session 实例到达情况，保留最近一次通过验证的 `session/title` 控制快照。seq 更新的事件会替换旧快照，标题时间戳计入列表新近程度；订阅基线会先丢弃 seq 超过其 `lastSeq` 的任何已保留标题，再接收可选的折叠标题。显式移除 Session 也会清除已保留标题。因此，面向客户端的 `SessionSummary.title` 只包含真实的持久标题；`displayTitle` 始终存在，并依次回退到 cwd basename 和 Session id。冷启动的持久会话会保持该回退值，直到打开或恢复会话，促使主机折叠并投影日志支持的标题。
+
+## 会话模型选择
+
+每个常驻 `Session` 都拥有一个 `modelSelection` 快照，其中包含当前提供方/模型目标、按提供方分组的目录、逐提供方失败记录，以及 `idle`／`loading`／`ready`／`selecting`／`error` 状态。历史记录会建立或刷新当前目标，打开选择器会刷新目录；选择失败会保留上一个目标和可用分组。目录与选择操作共用单调递增的代次，因此较旧响应无法覆盖较新的选择。重连重建会恢复 Host 报告的目标，同时不替换未变化的选择子结构。
+
+## 模型体验
+
+无，因为 Session 对象层会选择后续 Host 请求使用的提供方/模型路由，但不添加任何模型可见内容。
+
+#### KV Cache 影响
+
+更改目标可能改变提供方侧的缓存复用，或使其失效；该包本身不会改变提示词前缀。
+
+## 已知限制与暂缓事项
+
+- **`loader.unload` 是 stub（抛出 not-implemented）**：完整链路（fiber 释放 → 注册级联 → 样式移除）随 HMR 项目落地。
+- **scope 拆卸由阶段驱动，目前只能有一个占用者**：已 staged 的 Session 精确跟随 `list.current`（staging 就是打开信号：事件窗口打开 ⟺ Session 位于 stage）；在 staged 状态下被移除的 Session，其 scope 会冻结保留，直到 stage 转向其他 Session，而非直到真实观察者数量降为零。解析（`binding()`／`scope()`）只是纯寻址，可安全用于渲染；渲染层经 `currentProvideInfo` observable 读取当前 bundle。并发 pane 落地时，staged 状态可以扩展为多 pane 列表。
+- **插件组合包从该包执行值导入时必须使用 `/client` 子路径**：裸包名不在 loader external 表中，会内联第二个模块实例；其私有 scope-tag Symbol 永远无法匹配（空状态 P0 事故复盘）。

packages/client/runtime/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@deepseek-ai/dsh-client-runtime",
-  "description": "Client cordis boot and core services: SlotsService, SessionsService (scope tree + object layer), ClientLoader",
+  "description": "Client core services: SlotsService, SessionsService (scope tree + object layer)",
   "version": "0.0.1",
   "private": true,
   "type": "module",
@@ -15,10 +15,6 @@
       "types": "./lib/types/invariant.d.ts",
       "default": "./lib/invariant.js"
     },
-    "./loader": {
-      "types": "./lib/types/client/loader/index.d.ts",
-      "default": "./lib/loader.js"
-    },
     "./client": {
       "types": "./lib/types/client/index.d.ts",
       "default": "./lib/client.js"
@@ -36,11 +32,16 @@
   "license": "BSD-3-Clause",
   "dependencies": {
     "@deepseek-ai/dsh-client-connection": "workspace:^",
+    "@deepseek-ai/dsh-commands": "workspace:^",
     "@deepseek-ai/dsh-client-ui-slots": "workspace:^",
-    "@deepseek-ai/dsh-client-web-react": "workspace:^",
+    "@deepseek-ai/dsh-host-apiproxy": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-session-projection": "workspace:^",
+    "@deepseek-ai/dsh-session-title": "workspace:^",
+    "immer": "^10.1.1",
     "react": "^18.2.0",
-    "@deepseek-ai/dsh-session": "workspace:^"
+    "zustand": "~4.4.7"
   },
   "peerDependencies": {
     "@deepseek-ai/dsh-invariants": "^0.0.1",
@@ -55,7 +56,6 @@
     "lib/index.js",
     "lib/invariant.js",
     "lib/client.js",
-    "lib/loader.js",
     "lib/types/**/*.d.ts",
     "lib/types/**/*.d.ts.map",
     "src"

packages/client/runtime/src/client/agents/scope.ts

@@ -0,0 +1,70 @@
+/**
+ * Client Agent-scope primitive: mint a Cordis context tagged with the owning
+ * Agent's identity. The mechanism mirrors the host `dsh-scope` architecture
+ * (no-op plugin fiber + context tag + `Context.filter` routing predicate);
+ * the shape deliberately diverges: the filter lives on the actx itself
+ * instead of a separate carrier object, so scoped dispatch is plain cordis —
+ * `actx.bail(actx, event, payload)` / `actx.emit(actx, ...)` — with no
+ * wrapper. The host needs a detached carrier because its dispatch subject is
+ * the business Agent object; client scope events carry only ids, so the
+ * actx is the natural subject. The second divergence stands: the scope key
+ * is the branded `SessionId` (value compared), not an object identity — the
+ * agent and its session share one id (1:1, same axis; no separate AgentId
+ * brand), and a client scope's identity IS that wire id. Third divergence,
+ * deliberate: the client scopes the Agent IDENTITY, not a live Agent object
+ * — a cold session's host Agent is already disposed while its client actx
+ * stays alive for history viewing.
+ */
+import { Context as CordisContext } from 'cordis'
+import type { Context, Fiber } from 'cordis'
+import type { SessionId } from '@deepseek-ai/dsh-client-connection/client'
+
+/** Context tag written by {@link createScope}. */
+const kScope = Symbol('dsh.client.scope')
+
+/** A minted Agent scope and its disposal boundary. */
+export interface AgentScopeHandle {
+  /**
+   * Tagged context: scope-owned registrations and scoped dispatch both go
+   * through it (passing it as the dispatch subject routes to this agent's
+   * tagged listeners plus every untagged one).
+   */
+  ctx: Context
+  /** Backing fiber (dispose tears down every scope-owned registration). */
+  fiber: Fiber
+}
+
+/** Shared no-op plugin backing each Agent scope fiber. */
+function agentScope(): void {}
+
+/**
+ * Mint an Agent scope under `ctx`: a no-op plugin fiber whose context
+ * carries the agent tag and the dispatch filter — untagged listeners are
+ * admitted globally, tagged listeners only for a matching agent.
+ * Registrations through the returned ctx dispose with the fiber.
+ * @param ctx - client root context the scope fiber mounts under.
+ * @param key - owning agent identity (the routing tag; agent id === session id).
+ * @returns the tagged context and its backing fiber.
+ */
+export function createScope(ctx: Context, key: SessionId): AgentScopeHandle {
+  const fiber = ctx.plugin(agentScope)
+  return {
+    fiber,
+    ctx: fiber.ctx.extend({
+      [kScope]: key,
+      [CordisContext.filter](listenerCtx: Context): boolean {
+        const tag = scopeOf(listenerCtx)
+        return tag === undefined || tag === key
+      },
+    }),
+  }
+}
+
+/**
+ * Read the nearest agent tag inherited by a context.
+ * @param ctx - any client context.
+ * @returns its agent identity (the session id), or undefined for root contexts.
+ */
+export function scopeOf(ctx: Context): SessionId | undefined {
+  return (ctx as Context & { [kScope]?: SessionId })[kScope]
+}

packages/client/runtime/src/client/contract/store.ts

@@ -1,18 +1,32 @@
 /**
  * Snapshot store engine (zustand vanilla + immer + subscribeWithSelector +
- * rafFlush middleware + opt-in persist + dev freeze). The only data contract
- * consumed by React is {@link ObservableSnapshot}.
+ * rafFlush middleware + opt-in persist + dev freeze) plus the declarative
+ * shell over it: {@link defineStore} bakes an init/persist/actions literal
+ * into a {@link StoreHandle}, the registration-side store seat of the slot
+ * terminal design (§4). Lives in the React-free runtime (store-migration
+ * ruling: the data layer owns its engine; web-react is shell-only React
+ * glue): engine products are bare observables — subscribe/getSnapshot/
+ * update/set, NO selector hook. Hook synthesis is web-react's (the one
+ * uSES bridge, cached per source at the binding site).
  */
 import { createStore, type StoreApi } from 'zustand/vanilla'
 import { subscribeWithSelector } from 'zustand/middleware'
 import { shallow } from 'zustand/shallow'
 import { produce } from 'immer'
-import { bindSnapshotSelector } from '../bind.ts'
+import type {
+  ActionsDecl, BakedActions, StoreHandle, StoreInstance, StoreSpec,
+} from '@deepseek-ai/dsh-client-ui-slots'
+
+// Store contract types are ui-slots authority; re-exported beside the engine
+// so store consumers get one import surface.
+export type {
+  ActionsDecl, BakedActions, BoundActions, StoreFactory, StoreHandle, StoreInstance, StoreSpec,
+} from '@deepseek-ai/dsh-client-ui-slots'
 
 /** Minimal observable snapshot source: Session objects and snapshot stores both satisfy it. */
 export interface ObservableSnapshot<T> { getSnapshot(): T; subscribe(fn: () => void): () => void }
 
-/** Writable snapshot store with an attached typed selector hook. */
+/** Writable snapshot store (bare data face; React selector hooks are synthesized in web-react). */
 export interface SnapshotStore<T> extends ObservableSnapshot<T> {
   /**
    * Mutate the state through an immer draft.
@@ -24,14 +38,11 @@ export interface SnapshotStore<T> extends ObservableSnapshot<T> {
    * @param next - next state.
    */
   set(next: T): void
-  readonly useSelector: SnapshotSelectorHook<T>
 }
 
-/** Typed selector hook: equality defaults to Object.is; pass shallowEqual for object slices. */
-export type SnapshotSelectorHook<T> = <S>(sel: (s: T) => S, eq?: (a: S, b: S) => boolean) => S
-
 /**
- * Shallow equality for selector slices (re-export of zustand/shallow semantics).
+ * Shallow equality for selector slices (zustand/shallow semantics; travels
+ * with the engine so hook consumers need no zustand dependency).
  * @param a - left value.
  * @param b - right value.
  * @returns whether the values are shallowly equal.
@@ -91,7 +102,7 @@ export function createSnapshotStore<T>(
     }
   }
 
-  const store: SnapshotStore<T> = {
+  return {
     getSnapshot: () => api.getState(),
     subscribe: fn => subscribe(fn),
     update: (mutator) => {
@@ -102,10 +113,7 @@ export function createSnapshotStore<T>(
     set: (next) => {
       api.setState(devFreeze(next), true)
     },
-    useSelector: undefined as unknown as SnapshotSelectorHook<T>,
   }
-  ;(store as { useSelector: SnapshotSelectorHook<T> }).useSelector = bindSnapshotSelector(store)
-  return store
 }
 
 /**
@@ -152,3 +160,81 @@ function deepFreeze(value: unknown): void {
     deepFreeze((value as Record<PropertyKey, unknown>)[key])
   }
 }
+
+// ui-slots owns the contract; this module supplies the engine implementation.
+
+/** A live engine instance: the contract instance plus the raw engine store. */
+export interface EngineStoreInstance<T, A extends ActionsDecl<T>> extends StoreInstance<T, A> {
+  /** The underlying engine store (framework/test surface; components never see it). */
+  readonly store: SnapshotStore<T>
+}
+
+/** The engine-backed handle: create() narrowed to the engine instance. */
+export interface EngineStoreHandle<T, A extends ActionsDecl<T>> extends StoreHandle<T, A> {
+  /**
+   * Construct a live engine instance (see the contract JSDoc on
+   * {@link StoreHandle.create} for scopeKey/persist semantics).
+   *
+   * Known boundary: the persist key is the storage identity, so multiple live
+   * instances created under the same resolved key share (and cross-pollute)
+   * one localStorage entry. Instance uniqueness per key is the caller's
+   * responsibility — production is safe because the framework caches one
+   * instance per handle x scope key; tests wanting isolation use distinct
+   * scope keys or persist-free declarations (multi-create freedom is a
+   * feature there, so create() deliberately does not dedupe or throw).
+   * @param scopeKey - session id for session-scope instances; omitted for root scope.
+   * @returns the engine instance.
+   */
+  create(scopeKey?: string): EngineStoreInstance<T, A>
+}
+
+/**
+ * Declare a store: initial state, optional persistence, and the full write
+ * set as pure draft mutators. The returned handle is the registration
+ * currency of the store seat — its identity keys instance sharing. Satisfies
+ * ui-slots' DefineStore contract (the handle/instance are the engine-extended
+ * subtypes).
+ *
+ * The `A & ActionsDecl<T>` actions position is load-bearing: T resolves from
+ * `init` in the first inference round, and the intersection then contextually
+ * types each mutator's draft parameter (context-sensitive functions defer),
+ * so call sites write `(d, x: X) => { ... }` with no draft annotation. If a
+ * future TS version breaks this single-literal inference, the design's
+ * documented fallback is currying (`defineStore(init).actions({...})`).
+ * @param decl - init lambda (fresh state per instance), optional persist key, actions table.
+ * @returns the store handle.
+ */
+export function defineStore<T, A extends ActionsDecl<T>>(
+  decl: StoreSpec<T, A> & { actions: A & ActionsDecl<T> }): EngineStoreHandle<T, A> {
+  return {
+    spec: decl,
+    create(scopeKey?: string): EngineStoreInstance<T, A> {
+      const persistKey = decl.persist === undefined
+        ? undefined
+        : scopeKey === undefined ? decl.persist : `${decl.persist}.${scopeKey}`
+      const store = createSnapshotStore<T>(
+        decl.init(),
+        persistKey !== undefined ? { persist: { name: persistKey } } : undefined)
+      const actions = {} as Record<string, (...params: unknown[]) => void>
+      for (const key of Object.keys(decl.actions)) {
+        const mutate = decl.actions[key] as (draft: T, ...params: unknown[]) => void
+        actions[key] = (...params: unknown[]) => { store.update((draft) => { mutate(draft, ...params) }) }
+      }
+      return {
+        actions: actions as BakedActions<T, A>,
+        getSnapshot: () => store.getSnapshot(),
+        subscribe: fn => store.subscribe(fn),
+        store,
+        clearPersisted: () => {
+          if (persistKey === undefined || typeof localStorage === 'undefined') return
+          try {
+            localStorage.removeItem(persistKey)
+          } catch {
+            // Storage failures (private mode, quota teardown races) only skip
+            // cleanup — the same non-fatal contract as attachPersistence.
+          }
+        },
+      }
+    },
+  }
+}

packages/client/runtime/src/client/index.ts

@@ -1,52 +1,52 @@
-/**
- * Browser half: the whole runtime contract surface (api-contracts v3 §4) —
- * SlotsService, SessionsService (list store + scope tree + object layer),
- * the ClientLoader interface, and the cordis Context/Events merges. apply
- * mounts ctx.slots + ctx.sessions and wires the connection stream loop into
- * the object layer. The loader machinery implementation is NOT in the plugin
- * bundle — it ships via the package's `./loader` subpath, statically held by
- * the web shell (a loader cannot load itself).
- */
+/** Browser runtime services for slots, sessions, workspaces, and connection-stream delivery. */
 import type { Context } from 'cordis'
-import type { ConnectionHandle } from '@deepseek-ai/dsh-client-connection/client'
-import type { SessionBinding as GenericSessionBinding } from '@deepseek-ai/dsh-client-ui-slots'
-import type { SnapshotStore, UseSession } from '@deepseek-ai/dsh-client-web-react'
+import type { ConnectionHandle, SessionId } from '@deepseek-ai/dsh-client-connection/client'
+import type { MaybeSnapshotSelectorHook, SnapshotSelectorHook } from '@deepseek-ai/dsh-client-ui-slots'
 import { SlotsService } from './slots.ts'
 import { SessionsService } from './sessions/service.ts'
+import type { SessionListState } from './sessions/service.ts'
+import { WorkspacesService } from './workspaces/service.ts'
 import type { ConversationSnapshot, RunningToolCall, ToolResultNode } from './sessions/conversation.ts'
+import type { UseProjection } from './sessions/projection-store.ts'
 
 export { SlotsService } from './slots.ts'
-export { SessionsService, scopeOf } from './sessions/service.ts'
-export type { SessionBinding, SessionListState, SessionSummary } from './sessions/service.ts'
-export { SessionManager } from './sessions/manager.ts'
-export type { SessionListSnapshot } from './sessions/manager.ts'
-export { Session, PAGE_MESSAGES } from './sessions/session.ts'
-export type { SessionListEntry } from './sessions/lineage.ts'
+export type { RootOwnerProps } from './slots.ts'
+export { SessionCreateError, SessionsService, scopeOf, workspaceTitleOf } from './sessions/service.ts'
+export { createScope } from './agents/scope.ts'
+export type { AgentScopeHandle } from './agents/scope.ts'
+export { WorkspaceCreateError, WorkspacesService } from './workspaces/service.ts'
+export type { Session } from './sessions/session.ts'
 export type {
-  AssistantBlock, AssistantMessageNode, ContextMessageNode, ConversationNode, ConversationSnapshot,
-  OpenState, PartialAssistant, PendingInteraction, PromptError, RunningToolCall, SteeringMessageNode,
-  ToolResultNode, UnknownSurfaceNode, UserMessageNode,
+  SessionBinding, SessionListState, SessionProvideContribution, SessionProvideDescriptor, SessionSummary,
+} from './sessions/service.ts'
+export type { SessionListPhase } from './sessions/manager.ts'
+export type { WorkspaceListPhase } from './workspaces/manager.ts'
+export type { WorkspaceListState } from './workspaces/service.ts'
+export type { WorkspaceId, WorkspaceView } from '@deepseek-ai/dsh-client-connection/client'
+// Runtime owns the snapshot store; web-react only binds it to React.
+export { createSnapshotStore, defineStore, shallowEqual } from './contract/store.ts'
+export type {
+  EngineStoreHandle, EngineStoreInstance, ObservableSnapshot, SnapshotStore,
+} from './contract/store.ts'
+export type {
+  AssistantBlock, AssistantMessageNode, CodeSubCall, CommandNode, ComposerPhase, ContextMessageNode, ConversationNode,
+  ConversationSnapshot, QueuedMessage, RunningToolCall,
+  SteeringMessageNode, TodoItem, ToolResultNode, UnknownSurfaceNode, UserMessageNode,
 } from './sessions/conversation.ts'
+export { PendingWait } from './sessions/pending.ts'
+export type { PendingInteraction, PendingKind, PendingPayloads } from './sessions/pending.ts'
+// Projection value store (session-projection RFC, push model): host-computed
+// whole values per key; domains ship projection support with zero client code.
+export type {
+  ProjectionsBaseline, ProjectionValueStore, SessionProjectionMap, UseProjection,
+} from './sessions/projection-store.ts'
 export type { SessionId } from '@deepseek-ai/dsh-client-connection/client'
-export type { GoalView, GoalRef, GoalPhase, GoalBlockReason } from '@deepseek-ai/dsh-client-connection/client'
 
-// ---- Narrowed aliases (the single narrowing point of the slot type chain:
-// ui-slots/web-react stay generic and dependency-inverted; the client-tree
-// concrete types live here, where their subjects live) ----
-
-/**
- * The client cordis context face: the base Context plus the service keys
- * this package's declaration merge contributes (slots/sessions/loader) and
- * every later plugin's merge. A plain alias — the merges land on Context
- * itself inside the client program; the name marks intent at consumer seams.
- */
+/** Client-side Cordis context after declaration merging. */
 export type ClientContext = Context
 
-/** SessionBinding narrowed to the client context (inject factories dot services directly). */
-export type ClientSessionBinding = GenericSessionBinding<ClientContext>
-
-/** The conversation-snapshot selector hook (ConvViewProps/ToolViewProps take this). */
-export type UseConversationSession = UseSession<ConversationSnapshot>
+/** The conversation-snapshot selector hook (ConvViewProps/ToolRowProps take this). */
+export type UseConversationSession = SnapshotSelectorHook<ConversationSnapshot>
 
 /**
  * One tool call as the chat flow renders it: still-running (spinner card) or
@@ -55,6 +55,35 @@ export type UseConversationSession = UseSession<ConversationSnapshot>
  */
 export type ToolCallBlock = RunningToolCall | ToolResultNode
 
+declare module '@deepseek-ai/dsh-client-ui-slots' {
+  /**
+   * Session standard kit, real members (ui-slots declares the empty seat;
+   * the runtime — where the subjects live — merges the concrete types):
+   * every session-scope slot component receives these from the framework.
+   */
+  interface SessionStandardProps {
+    useSession: SnapshotSelectorHook<ConversationSnapshot>
+    /** The framework-resolved session id (owners never pass it). */
+    sessionId: SessionId
+    /** The fifth framework hook seat: key-addressed projection reader (undefined = capability absent). */
+    useProjection: UseProjection
+  }
+  /** Standard kit for slots that remain mounted while current session changes. */
+  interface SessionMaybeStandardProps {
+    useSession: MaybeSnapshotSelectorHook<ConversationSnapshot>
+    /** Current session id; absent in the no-session state. */
+    sessionId: SessionId | undefined
+    /** Key-addressed projection reader; every key reads absent while no session is current. */
+    useProjection: UseProjection
+  }
+  /** Props injected into every global slot component. */
+  interface GlobalStandardProps {
+    useSessions: SnapshotSelectorHook<SessionListState>
+    /** Selector hook over real Workspaces and their independent baseline lifecycle. */
+    useWorkspaces: SnapshotSelectorHook<import('./workspaces/service.ts').WorkspaceListState>
+  }
+}
+
 declare module 'cordis' {
   interface Events {
     /**
@@ -63,67 +92,57 @@ declare module 'cordis' {
      * @param key - the mutated SlotMap key.
      */
     'slots/changed'(key: string): void
+    /**
+     * The host command registry changed (host/commands-changed passthrough).
+     * Pure invalidation signal: subscribers refetch `command.list` in the
+     * background rather than diffing.
+     * @mode emit
+     */
+    'commands/changed'(): void
+    /**
+     * A connection generation was (re-)established. Wire-derived caches must
+     * treat their state as stale and repull (commands directory; the queue
+     * mirrors reset themselves through the session resync path).
+     * @mode emit
+     */
+    'connection/reset'(): void
   }
   interface Context {
     slots: import('./slots.ts').SlotsService
     sessions: import('./sessions/service.ts').SessionsService
-    loader: ClientLoader
+    workspaces: import('./workspaces/service.ts').WorkspacesService
   }
 }
 
-/** One __DSH_BOOT__ manifest row. */
-export interface BootPluginEntry { id: string; url: string; inject: string[]; immediately?: boolean }
-
-/** Per-plugin load status store shape. */
-export type LoaderStatus = Record<string, 'loading' | 'active' | 'failed'>
-
-/**
- * Client bundle loader. The immediately group loads first (parallel fetch,
- * apply in inject topology order); remaining plugins follow in inject
- * topology. Loaded bundle export surfaces are registered back into the
- * require module table. Implementation lives in the `./loader` subpath
- * (shell-held machinery).
- */
-export interface ClientLoader {
-  /** Start loading from window.__DSH_BOOT__ (non-blocking). */
-  start(): void
-  /**
-   * Load one plugin bundle (script inject, factory handoff, ctx.plugin, style registration).
-   * @param id - plugin id (package name).
-   */
-  load(id: string): Promise<void>
-  /**
-   * Unload a plugin. P-I: not implemented (full chain lands with HMR).
-   * @param id - plugin id.
-   */
-  unload(id: string): Promise<void>
-  /** Resolves when every manifest plugin reached active (AppRoot gates the real UI on this). */
-  settled(): Promise<void>
-  /**
-   * Read a loaded module's export surface from the module table (same
-   * implementation the bundle-facing require uses; unknown spec throws).
-   * @param spec - module specifier (package name or seeded library id).
-   */
-  requireModule(spec: string): unknown
-  /** Per-plugin status store. */
-  readonly status: SnapshotStore<LoaderStatus>
-}
-
 /** Required services: the wire handle mounted by the connection plugin. */
 export const inject = ['connection']
 
-/**
- * Client plugin body: mount slots + sessions, start the stream loop.
- * @param ctx - client cordis context.
+/** Mounts the browser runtime services and connection stream.
+ * @param ctx - Client Cordis context.
  */
 export function apply(ctx: Context): void {
   ctx.plugin(SlotsService)
   const connection = ctx.get('connection') as ConnectionHandle
   const sessions = new SessionsService(ctx, connection.api)
+  const workspaces = new WorkspacesService(ctx, connection.api, sessions)
+  ctx.effect(
+    () => workspaces.startInitialSelection(),
+    'runtime: initial Workspace selection',
+  )
   const loop = connection.start({
-    onMuxEnvelope: (envelope) => { sessions.manager.handleMuxEnvelope(envelope) },
-    onHostEnvelope: (envelope) => { sessions.manager.handleHostEnvelope(envelope) },
-    onConnected: () => { sessions.manager.handleConnected() },
+    onMuxEnvelope: (envelope) => { sessions.handleMuxEnvelope(envelope) },
+    onHostEnvelope: (envelope) => {
+      sessions.handleHostEnvelope(envelope)
+      workspaces.handleHostEnvelope(envelope)
+      // Typed-event bridge: the session layer ignores registry frames (no
+      // session routing); consumers (command directory caches) subscribe on ctx.
+      if (envelope.payload.type === 'host/commands-changed') ctx.emit('commands/changed')
+    },
+    onConnected: () => {
+      sessions.handleConnected()
+      workspaces.handleConnected()
+      ctx.emit('connection/reset')
+    },
   })
   ctx.effect(() => () => { loop.stop() }, 'runtime: connection stream loop')
 }

packages/client/runtime/src/client/loader/index.ts

@@ -1,247 +0,0 @@
-/**
- * ClientLoader implementation (shell-held machinery — the loader cannot load
- * itself, so the web shell imports this subpath statically and mounts the
- * instance as ctx.loader; the runtime package's own client bundle never
- * includes it).
- *
- * Load chain per plugin: fetch bundle text → execute (script injection) → the
- * bundle calls window.DSHClientProxy.loadPlugin({id, factory}) (single-slot
- * handoff, id reconciled) → factory(require) with require bound to the module
- * table → ctx.plugin(exports.apply) → the export surface is registered into
- * the module table under the plugin id (inject topology guarantees later
- * loaders can require earlier ones) → <style data-plugin> ownership recorded.
- *
- * start(): the `immediately` group is fetched in parallel and executed in
- * group-internal inject topology (execution is serial — the handoff slot is
- * single); a full-group barrier precedes the remaining plugins, which then
- * load one by one in inject topology.
- */
-import type { Context } from 'cordis'
-import { createSnapshotStore } from '@deepseek-ai/dsh-client-web-react'
-import type { BootPluginEntry, ClientLoader, LoaderStatus } from '../index.ts'
-
-export type { BootPluginEntry, ClientLoader, LoaderStatus } from '../index.ts'
-
-/** The shape a client bundle hands to window.DSHClientProxy.loadPlugin. */
-export interface ClientPluginHandoff {
-  /** Plugin id (package name) — must match the manifest row being loaded. */
-  id: string
-  /**
-   * Closure factory: receives the DI require and returns the module's export
-   * surface; an `apply` export is applied as a cordis plugin.
-   */
-  factory: (require: (spec: string) => unknown) => Record<string, unknown>
-}
-
-/** Window surface the loader owns (bundle side of the handoff protocol). */
-interface DshWindow {
-  __DSH_BOOT__?: { plugins: BootPluginEntry[] }
-  DSHClientProxy?: { loadPlugin(handoff: ClientPluginHandoff): void }
-}
-
-/** Options for createClientLoader (assembled by the web shell at boot). */
-export interface ClientLoaderOptions {
-  /** Client root context: plugin applies mount under it. */
-  ctx: Context
-  /**
-   * Seeded module table: pure-library entities (react, react-dom, cordis,
-   * ui-slots, web-react, ui-primitives). The loader takes ownership and
-   * registers loaded bundle export surfaces alongside them.
-   */
-  modules: Record<string, unknown>
-  /**
-   * Boot manifest; defaults to window.__DSH_BOOT__. Fixture pages inject the
-   * same protocol shape.
-   */
-  boot?: { plugins: BootPluginEntry[] }
-  /** Bundle fetch seam (parallelizable half). Defaults to same-origin fetch().text(). */
-  fetchBundle?: (url: string) => Promise<string>
-  /**
-   * Bundle execution seam (serial half; execution synchronously performs the
-   * loadPlugin handoff). Defaults to a <script> element carrying the code.
-   */
-  executeBundle?: (code: string, url: string) => void
-}
-
-/** Per-plugin bookkeeping across the load chain. */
-interface PluginRecord {
-  entry: BootPluginEntry
-  state: 'idle' | 'loading' | 'active' | 'failed'
-  fetch?: Promise<string>
-  load?: Promise<void>
-}
-
-const NOT_LOADED = Symbol('dsh.loader.not-loaded')
-
-/**
- * Build the client bundle loader.
- * @param options - ctx, seeded module table, boot manifest, fetch/execute seams.
- * @returns the ClientLoader the shell mounts as ctx.loader.
- */
-export function createClientLoader(options: ClientLoaderOptions): ClientLoader {
-  const { ctx } = options
-  const win = globalThis as DshWindow
-  const boot = options.boot ?? win.__DSH_BOOT__
-  if (boot === undefined) throw new Error('client-loader: no boot manifest (window.__DSH_BOOT__ missing)')
-
-  const modules = new Map<string, unknown>(Object.entries(options.modules))
-  const records = new Map<string, PluginRecord>()
-  for (const entry of boot.plugins) {
-    if (records.has(entry.id)) throw new Error(`client-loader: duplicate manifest id "${entry.id}"`)
-    records.set(entry.id, { entry, state: 'idle' })
-  }
-
-  const status = createSnapshotStore<LoaderStatus>({})
-  const publish = (id: string, state: 'loading' | 'active' | 'failed'): void => {
-    status.update((draft) => { draft[id] = state })
-  }
-
-  // Single-slot handoff: bundle execution synchronously calls loadPlugin;
-  // doLoad arms the slot before executing and reconciles the id after.
-  let slot: ClientPluginHandoff | typeof NOT_LOADED = NOT_LOADED
-  if (win.DSHClientProxy !== undefined) throw new Error('client-loader: window.DSHClientProxy already installed (double boot?)')
-  win.DSHClientProxy = {
-    loadPlugin: (handoff: ClientPluginHandoff): void => {
-      if (slot !== NOT_LOADED) {
-        throw new Error(`client-loader: overlapping loadPlugin handoff (got "${handoff.id}" while a previous handoff is unclaimed)`)
-      }
-      slot = handoff
-    },
-  }
-
-  const fetchBundle = options.fetchBundle ?? (async (url: string): Promise<string> => {
-    const res = await fetch(url)
-    if (!res.ok) throw new Error(`client-loader: bundle fetch ${url} answered ${String(res.status)}`)
-    return res.text()
-  })
-
-  const executeBundle = options.executeBundle ?? ((code: string, url: string): void => {
-    const el = document.createElement('script')
-    // Inline execution (not src) so the fetch half stays parallelizable; the
-    // sourceURL comment keeps devtools stack frames attributed to the bundle.
-    el.textContent = `${code}\n//# sourceURL=${url}`
-    document.head.appendChild(el)
-  })
-
-  const requireModule = (spec: string): unknown => {
-    if (!modules.has(spec)) {
-      throw new Error(`client-loader: module "${spec}" is not available — not a seeded library and no loaded plugin registered it (check dshClient.inject ordering)`)
-    }
-    return modules.get(spec)
-  }
-
-  /** Tag styles the bundle injected during execution (unload bookkeeping; plugin CSS lands untagged). */
-  const claimStyles = (id: string): void => {
-    if (typeof document === 'undefined') return
-    for (const el of document.querySelectorAll('style:not([data-plugin])')) {
-      el.setAttribute('data-plugin', id)
-    }
-  }
-
-  /** Start (or reuse) the parallelizable fetch half. */
-  const prefetch = (record: PluginRecord): Promise<string> =>
-    (record.fetch ??= fetchBundle(record.entry.url))
-
-  async function doLoad(record: PluginRecord): Promise<void> {
-    const { id } = record.entry
-    record.state = 'loading'
-    publish(id, 'loading')
-    try {
-      // Dependencies must already be active (start() sequences this; direct
-      // load() callers get the same fail-loud check).
-      for (const dep of record.entry.inject) {
-        const depRecord = records.get(dep)
-        if (depRecord === undefined) throw new Error(`client-loader: "${id}" injects unknown plugin "${dep}"`)
-        if (depRecord.state !== 'active') throw new Error(`client-loader: "${id}" loaded before its dependency "${dep}" is active`)
-      }
-      const code = await prefetch(record)
-      executeBundle(code, record.entry.url)
-      if (slot === NOT_LOADED) throw new Error(`client-loader: bundle ${record.entry.url} executed without calling DSHClientProxy.loadPlugin`)
-      const handoff = slot
-      slot = NOT_LOADED
-      if (handoff.id !== id) throw new Error(`client-loader: bundle id mismatch — manifest "${id}" vs handoff "${handoff.id}"`)
-      const exports = handoff.factory(requireModule)
-      if (typeof exports.apply !== 'function') throw new Error(`client-loader: plugin "${id}" exports no apply function`)
-      // The whole export surface is the plugin: cordis object-plugin form
-      // keeps the bundle's exported `inject`/`name` (an apply-only pass would
-      // silently drop the dependency declaration — postmortem 0001).
-      const fiber = ctx.plugin(exports as { apply: (ctx: Context) => void })
-      await fiber.await()
-      // Register under both specifier forms bundles emit: the bare package
-      // name (deep-import rewrites) and the /client subpath (CLIENT_EXTERNALS
-      // form) — the loaded surface IS the client half either way.
-      modules.set(id, exports)
-      modules.set(`${id}/client`, exports)
-      claimStyles(id)
-      record.state = 'active'
-      publish(id, 'active')
-    } catch (error) {
-      record.state = 'failed'
-      publish(id, 'failed')
-      throw error
-    }
-  }
-
-  const load = (id: string): Promise<void> => {
-    const record = records.get(id)
-    if (record === undefined) return Promise.reject(new Error(`client-loader: unknown plugin "${id}"`))
-    record.load ??= doLoad(record)
-    return record.load
-  }
-
-  /** Topologically order `ids` by inject (edges inside the set only — an early-group member never waits on a later-group one). */
-  const topo = (ids: string[]): string[] => {
-    const pool = new Set(ids)
-    const ordered: string[] = []
-    const done = new Set<string>()
-    const visiting = new Set<string>()
-    const visit = (id: string): void => {
-      if (done.has(id)) return
-      if (visiting.has(id)) throw new Error(`client-loader: inject cycle through "${id}"`)
-      visiting.add(id)
-      const record = records.get(id)
-      /* v8 ignore next -- ids come from records; unknown ids are caught per-dep below. */
-      if (record === undefined) throw new Error(`client-loader: manifest references unknown plugin "${id}"`)
-      for (const dep of record.entry.inject) {
-        if (!records.has(dep)) throw new Error(`client-loader: "${id}" injects unknown plugin "${dep}"`)
-        if (pool.has(dep)) visit(dep)
-      }
-      visiting.delete(id)
-      done.add(id)
-      ordered.push(id)
-    }
-    for (const id of ids) visit(id)
-    return ordered
-  }
-
-  let settledPromise: Promise<void> | undefined
-
-  async function run(): Promise<void> {
-    const all = [...records.values()]
-    const early = all.filter(r => r.entry.immediately === true)
-    const rest = all.filter(r => r.entry.immediately !== true)
-    // Early group: parallel fetch (all requests in flight at once), serial
-    // inject-topology execution, full-group barrier before anything else.
-    const earlyOrder = topo(early.map(r => r.entry.id))
-    for (const record of early) void prefetch(record).catch(() => {}) // surfaced by the awaited load below
-    for (const id of earlyOrder) await load(id)
-    // Remaining plugins: one by one in inject topology.
-    for (const id of topo(rest.map(r => r.entry.id))) await load(id)
-  }
-
-  return {
-    start: () => {
-      settledPromise ??= run()
-      // Failures surface through settled()/status — start() itself is fire-and-forget.
-      settledPromise.catch(() => {})
-    },
-    load,
-    unload: (id: string) => Promise.reject(new Error(`client-loader: unload("${id}") is not implemented (lands with HMR)`)),
-    settled: () => {
-      if (settledPromise === undefined) throw new Error('client-loader: settled() before start()')
-      return settledPromise
-    },
-    requireModule,
-    status,
-  }
-}

packages/client/runtime/src/client/ordered-baseline.ts

@@ -0,0 +1,43 @@
+/**
+ * Merge an authoritative baseline without moving identities already visible to
+ * the client. Baseline-only identities are inserted relative to the nearest
+ * following known identity; identities absent from the baseline are removed.
+ *
+ * @param current - the established client order.
+ * @param baseline - the latest authoritative rows.
+ * @param keyOf - stable identity selector.
+ * @returns baseline-valued rows with the established relative order retained.
+ */
+export function mergeOrderedBaseline<T>(
+  current: readonly T[],
+  baseline: readonly T[],
+  keyOf: (value: T) => unknown,
+): T[] {
+  const baselineByKey = new Map<unknown, T>()
+  for (const value of baseline) baselineByKey.set(keyOf(value), value)
+
+  const merged = current
+    .map(value => baselineByKey.get(keyOf(value)))
+    .filter((value): value is T => value !== undefined)
+  const mergedKeys = new Set(merged.map(keyOf))
+
+  for (let index = 0; index < baseline.length; index++) {
+    const value = baseline[index]
+    /* v8 ignore next -- dense-array guard: index is bounded by baseline.length. */
+    if (value === undefined || mergedKeys.has(keyOf(value))) continue
+    let insertion = merged.length
+    for (let following = index + 1; following < baseline.length; following++) {
+      const candidate = baseline[following]
+      /* v8 ignore next -- dense-array guard: following is bounded by baseline.length. */
+      if (candidate === undefined) continue
+      const known = merged.findIndex(item => keyOf(item) === keyOf(candidate))
+      if (known !== -1) {
+        insertion = known
+        break
+      }
+    }
+    merged.splice(insertion, 0, value)
+    mergedKeys.add(keyOf(value))
+  }
+  return merged
+}

packages/client/runtime/src/client/sessions/conversation.ts

@@ -3,8 +3,15 @@
 // substructures keep their references (the React.memo premise). callId/approvalId stay plain
 // string here (narrow to real brands when convenient).
 
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
-import type { GoalView, RpcError, RpcId, SessionId, ToolCallView, ToolResultView } from '@deepseek-ai/dsh-client-connection/client'
+import type { TodoItem } from '@deepseek-ai/dsh-session/types'
+import type {
+  RpcError, SessionId, ToolCallView, ToolResultView,
+} from '@deepseek-ai/dsh-client-connection/client'
+import type { PendingInteraction } from './pending.ts'
+
+export type { TodoItem }
 
 /** Assistant content blocks sorted by what the UI cares about
  *  (text body / collapsible reasoning / tool-call card head / other fallback). */
@@ -41,6 +48,8 @@ export function toAssistantBlock(block: ContentBlock): AssistantBlock {
 export interface UserMessageNode {
   kind: 'user'
   seq: number
+  /** Unix epoch ms from the source session event. */
+  time: number
   content: readonly ContentBlock[]
   source: unknown
 }
@@ -49,6 +58,8 @@ export interface UserMessageNode {
 export interface AssistantMessageNode {
   kind: 'assistant'
   seq: number
+  /** Unix epoch ms from the source session event (or turn/end when frozen from a partial). */
+  time: number
   turn: number
   step: number
   blocks: readonly AssistantBlock[]
@@ -62,6 +73,8 @@ export interface AssistantMessageNode {
 export interface SteeringMessageNode {
   kind: 'steering'
   seq: number
+  /** Unix epoch ms from the source session event. */
+  time: number
   turn: number
   content: readonly ContentBlock[]
   source: unknown
@@ -71,18 +84,23 @@ export interface SteeringMessageNode {
 export interface ContextMessageNode {
   kind: 'context'
   seq: number
+  /** Unix epoch ms from the source session event. */
+  time: number
   content: readonly ContentBlock[]
   source: unknown
-  meta?: unknown
 }
 
 /** A tool result paired (when in-window) with its call head. */
 export interface ToolResultNode {
   kind: 'tool-result'
   seq: number
+  /** Unix epoch ms from the tool/result session event. */
+  time: number
   callId: string
   /** Call head backfilled from the in-window tool/call; null when window truncation left the call outside (card head shows callId). */
   call: { name: string; argsRaw: string } | null
+  /** Unix epoch ms of the paired tool/call when the call is still in-window; used for call-row duration. */
+  callTime: number | null
   content: readonly ContentBlock[]
   isError: boolean
   error?: { name: string; code: string }
@@ -97,10 +115,37 @@ export interface ToolResultNode {
 export interface UnknownSurfaceNode {
   kind: 'unknown'
   seq: number
+  /** Unix epoch ms from the source session event when known. */
+  time: number
   type: string
   data: unknown
 }
 
+/**
+ * One slash-command lifecycle folded from the log-only `command/run` /
+ * `command/done` pair (paired by commandId, mirroring tool call↔result).
+ * Log-only events never enter the surface fold, so the FoldAdapter indexes
+ * them separately and merges the nodes into the flow by seq. A window cut
+ * between the pair soft-falls like tool pairs: a done with no in-window run
+ * still builds a node (name/args null), and a run with no done renders as
+ * still executing.
+ */
+export interface CommandNode {
+  kind: 'command'
+  /** Seq of the command/run event; the done event's seq when only the done is in-window. */
+  seq: number
+  /** Unix epoch ms of the anchoring event. */
+  time: number
+  /** Pairing id minted by the host executor. */
+  commandId: CommandId
+  /** Command name (run payload's structured field); null when the run fell outside the window. */
+  name: string | null
+  /** Verbatim rawInput after the name, separator whitespace included (run payload); null when the run fell outside the window. */
+  args: string | null
+  /** Settlement outcome (done payload); null while the command is still executing. */
+  outcome: { kind: 'success' | 'error'; text?: string } | null
+}
+
 /** Finalized conversation node union (kind discriminates; seq is the React key). */
 export type ConversationNode =
   | UserMessageNode
@@ -108,8 +153,24 @@ export type ConversationNode =
   | SteeringMessageNode
   | ContextMessageNode
   | ToolResultNode
+  | CommandNode
   | UnknownSurfaceNode
 
+/**
+ * One `run_code` sub-dispatch materialized in the native call-block shapes so
+ * every consumer (tool rows, details panel) renders it through the exact
+ * components that render a native call: a started-but-unsettled sub-call is a
+ * {@link RunningToolCall} (rows derive the running state from the shape,
+ * exactly as for native calls) and its `tool/code-dispatch` settlement
+ * replaces it in place with the {@link ToolResultNode} form. Never part of
+ * the surface `nodes` flow — sub-calls live under their parent via
+ * {@link ConversationSnapshot.codeDispatches}. `callId` is the deterministic
+ * sub-call id (`<parent>:code:<n>`); the call side carries the sub-tool name
+ * and its JSON-stringified logged arguments; `content`/`isError` are the
+ * settled sub-call's complete logged outcome.
+ */
+export type CodeSubCall = RunningToolCall | ToolResultNode
+
 /** In-flight tool card material: tool/call seen, tool/result not yet. */
 export interface RunningToolCall {
   callId: string
@@ -117,15 +178,18 @@ export interface RunningToolCall {
   argsRaw: string
   turn: number
   step: number
+  /** Unix epoch ms when the tool/call event was logged. */
+  time: number
   /** Host-computed render intent riding the tool/call frame; null = generic JSON card. */
   callView: ToolCallView | null
 }
 
-/** Approval/question placeholder cards (visible, not answerable;
- *  rpcId = the requested frame's envelope id, the future respond backfill key). */
-export type PendingInteraction =
-  | { kind: 'approval'; rpcId: RpcId; approvalId: string; toolName: string; callId?: string; reason?: string }
-  | { kind: 'question'; rpcId: RpcId; questions: readonly unknown[] }
+
+/** One queued-message row mirrored from `session/queued` frames (key: the enqueueing prompt's rpcId when wire-sourced). */
+export interface QueuedMessage {
+  readonly key: string
+  readonly preview: string
+}
 
 /** In-progress assistant output (chunk accumulator product). */
 export interface PartialAssistant {
@@ -137,6 +201,28 @@ export interface PartialAssistant {
 /** History-open lifecycle of a Session window. */
 export type OpenState = 'cold' | 'loading' | 'open' | 'error'
 
+/**
+ * Input-area shape of an OPEN session, derived at snapshot assembly (the one
+ * place that knows the predicate — consumers switch, never re-derive):
+ *
+ * - `blank`: no activity ever (no nodes, no partial, not running, no pending
+ *   waits, no prompt attempt) — the UI renders the blank-session guidance
+ *   hero.
+ * - `engaging`: the first prompt was initiated but no content landed yet —
+ *   the UI holds the composer through the accept → running → first-event
+ *   frames. Entered synchronously before prompt()'s first await.
+ * - `active`: content exists (nodes, partial, running turn, or pending
+ *   waits) — the ordinary conversation view.
+ *
+ * Monotone within a session object: blank → engaging → active, no returns.
+ * A failed first prompt stays `engaging` (composer + error strip — retry
+ * semantics; bouncing back to the hero would discard the error context).
+ * Sessions whose window is not open (`loading`/`error`) are outside phase
+ * jurisdiction: consumers branch on {@link ConversationSnapshot.openState}
+ * first (phase still reports `active`-ish facts but must not be rendered).
+ */
+export type ComposerPhase = 'blank' | 'engaging' | 'active'
+
 /** Send/stop failure surfaced in the input error strip; op picks the user-facing copy (发送失败 vs 停止失败). */
 export interface PromptError {
   op: 'send' | 'stop'
@@ -152,8 +238,19 @@ export interface ConversationSnapshot {
   foldDegraded: boolean
   partial: PartialAssistant | null
   runningCalls: readonly RunningToolCall[]
+  /**
+   * `run_code` sub-dispatches grouped under their parent callId, in dispatch
+   * order. Populated from in-window `tool/code-dispatch` events (live and
+   * replay identically); the per-parent array reference is stable across
+   * unrelated snapshot swaps (memo premise, same regime as `nodes`).
+   */
+  codeDispatches: ReadonlyMap<string, readonly CodeSubCall[]>
   pending: readonly PendingInteraction[]
+  /** Read-only inbox mirror (session/queued frames + mux-open baseline; cleared by the leave-running flip). */
+  queue: readonly QueuedMessage[]
   running: boolean
+  /** Input-area shape (see {@link ComposerPhase}); derived here, switched on by consumers. */
+  composerPhase: ComposerPhase
   /** Set after host/session-removed; the UI grays out and disables input. */
   removed: boolean
   openState: OpenState
@@ -161,8 +258,16 @@ export interface ConversationSnapshot {
   hasMore: boolean
   loadingOlder: boolean
   promptError: PromptError | null
+  /**
+   * Whether this session still has an empty log (no user message yet).
+   * Mirrors the host summary's derived blank bit: seeded from `session.list`
+   * / the `host/session-added` frame, flipped false by the first ACCEPTED
+   * prompt locally (on the RPC success response — acceptance proves the
+   * user message is in the host log; a rejected first prompt keeps the
+   * session blank and reusable) and by any `running: true` status remotely,
+   * and re-aligned by every list re-pull (the summary stays authoritative).
+   * Blank sessions are hidden from session lists and reused by New Session.
+   */
+  blank: boolean
   lastAgentError: string | null
-  /** Current goal projection (fetched on open / refreshed when a live context/message carries
-   *  goal/change meta). undefined = not yet loaded. */
-  goal: GoalView | null | undefined
 }

packages/client/runtime/src/client/sessions/fold-adapter.ts

@@ -8,8 +8,9 @@ import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
 // go through it — the package root points at lib/index.js (needs a build) which the vite
 // browser bundle cannot resolve; surface.ts has no Node dependencies.
 import { SurfaceManager, isSurfaceEligibleType } from '@deepseek-ai/dsh-session/surface'
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type { ToolCallView, ToolEventView, ToolResultView } from '@deepseek-ai/dsh-client-connection/client'
-import type { ConversationNode } from './conversation.ts'
+import type { CommandNode, ConversationNode } from './conversation.ts'
 import { toAssistantBlocks } from './conversation.ts'
 
 /** In-window tool/call index entry (result-card backfill + runningCalls material). */
@@ -18,14 +19,16 @@ export interface CallIndexEntry {
   argsRaw: string
   turn: number
   step: number
+  /** Unix epoch ms of the tool/call event. */
+  time: number
   /** Wire view riding the tool/call (envelope-level; never inside the event). */
   callView: ToolCallView | null
 }
 
-/** Non-surface-eligible sentinel event (safely skipped by surfaceOpOf's undefined branch).
- *  'noop/padding' is not a real event type on purpose: a genuine type with fake data would
- *  surface as garbage the day anyone adds handling for it (design §D.1; the cast is the one
- *  place a synthetic event enters the window). */
+/** Non-surface sentinel used to preserve paged-window sequence offsets.
+ * `noop/padding` is deliberately not a real event type, so it cannot acquire
+ * surface behavior; this cast is the only synthetic event entry point.
+ */
 function paddingEvent(seq: number): SessionEvent {
   return { type: 'noop/padding', seq, time: 0, data: {} } as unknown as SessionEvent
 }
@@ -38,36 +41,53 @@ function materializeNode(
 ): ConversationNode {
   switch (event.type) {
     case 'user/message':
-      return { kind: 'user', seq: event.seq, content: event.data.content, source: event.data.source }
+      // Injected context (plugin/goal source) folds to a context node, not a
+      // user message; only a direct human prompt is a user node.
+      if (event.data.source.kind !== 'user') {
+        return {
+          kind: 'context', seq: event.seq, time: event.time,
+          content: event.data.content, source: event.data.source,
+        }
+      }
+      return {
+        kind: 'user', seq: event.seq, time: event.time,
+        content: event.data.content, source: event.data.source,
+      }
     case 'assistant/message':
       return {
-        kind: 'assistant', seq: event.seq, turn: event.data.turn, step: event.data.step,
-        blocks: toAssistantBlocks(event.data.content), usage: event.data.usage,
+        kind: 'assistant', seq: event.seq, time: event.time,
+        turn: event.data.turn, step: event.data.step,
+        blocks: toAssistantBlocks(event.data.message.content), usage: event.data.usage,
       }
     case 'steering/message':
-      return { kind: 'steering', seq: event.seq, turn: event.data.turn, content: event.data.content, source: event.data.source }
-    case 'context/message':
       return {
-        kind: 'context', seq: event.seq, content: event.data.content, source: event.data.source,
-        meta: event.data.meta,
+        kind: 'steering', seq: event.seq, time: event.time, turn: event.data.turn,
+        content: event.data.message.content, source: event.data.message.source,
       }
     case 'tool/result': {
-      const call = callIndex.get(String(event.data.callId))
+      const result = event.data.message.content[0]
+      const callId = String(event.data.message.source.callId)
+      const call = callIndex.get(callId)
       return {
-        kind: 'tool-result', seq: event.seq, callId: String(event.data.callId),
+        kind: 'tool-result', seq: event.seq, time: event.time,
+        callId,
         call: call ? { name: call.name, argsRaw: call.argsRaw } : null,
-        content: event.data.content, isError: event.data.isError,
+        callTime: call?.time ?? null,
+        content: result.content, isError: result.isError === true,
         ...(event.data.error !== undefined ? { error: event.data.error } : {}),
         meta: event.data.meta,
         callView: call?.callView ?? null,
         resultView,
       }
     }
-    /* v8 ignore next 2 -- defensive arm: fold output only carries the five
+    /* v8 ignore next 2 -- defensive arm: fold output only carries the four
     surface-eligible types, and each has a case above; reachable only if core
     adds an eligible type. */
     default:
-      return { kind: 'unknown', seq: event.seq, type: event.type, data: (event as { data?: unknown }).data }
+      return {
+        kind: 'unknown', seq: event.seq, time: event.time,
+        type: event.type, data: (event as { data?: unknown }).data,
+      }
   }
 }
 
@@ -82,6 +102,15 @@ export class FoldAdapter {
   private callIdx = new Map<string, CallIndexEntry>()
   /** Wire result views keyed by the tool/result event's seq (views ride the envelope, not the event). */
   private resultViews = new Map<number, ToolResultView>()
+  /**
+   * Command lifecycle nodes by commandId (insertion = run order). The
+   * `command/run`/`command/done` pair is log-only, so the surface fold never
+   * emits it; this index folds the pair (done settles its run's node in
+   * place) and nodes() merges the products into the flow by seq. Window cuts
+   * soft-fall like tool pairs: a done with no in-window run still builds a
+   * node.
+   */
+  private commandIdx = new Map<string, CommandNode>()
   /** Window revision (bumped on reset/append) keying the nodes() result cache: an unchanged
    *  window returns the previous ARRAY reference, not just cached elements — the snapshot's
    *  reference-stability contract (§A.9.4) starts here. */
@@ -111,10 +140,14 @@ export class FoldAdapter {
     this.degraded = false
     this.callIdx = new Map()
     this.resultViews.clear()
+    this.commandIdx = new Map()
     for (let i = 0; i < events.length; i++) {
       const event = events[i]
       /* v8 ignore next -- dense-array guard: i stays within events.length, so the undefined arm needs a sparse array no caller builds. */
-      if (event !== undefined) this.indexCall(event, views?.[i])
+      if (event !== undefined) {
+        this.indexCall(event, views?.[i])
+        this.indexCommand(event)
+      }
     }
   }
 
@@ -128,6 +161,7 @@ export class FoldAdapter {
     this.rev++
     this.padded.push(event)
     this.indexCall(event, view)
+    this.indexCommand(event)
   }
 
   /**
@@ -163,7 +197,23 @@ export class FoldAdapter {
       this.nodeCache.set(seq, node)
       out.push(node)
     }
-    const value = { nodes: out, degraded: this.degraded }
+    // Command nodes fold outside the surface (log-only events); merge by seq.
+    // Both inputs are seq-ascending (surface order and run-index insertion
+    // order share the log order), so one linear merge keeps flow order.
+    let nodes = out
+    if (this.commandIdx.size > 0) {
+      nodes = []
+      const commands = [...this.commandIdx.values()]
+      let next = 0
+      for (const node of out) {
+        for (let cmd = commands[next]; cmd !== undefined && cmd.seq < node.seq; cmd = commands[++next]) {
+          nodes.push(cmd)
+        }
+        nodes.push(node)
+      }
+      for (let cmd = commands[next]; cmd !== undefined; cmd = commands[++next]) nodes.push(cmd)
+    }
+    const value = { nodes, degraded: this.degraded }
     this.nodesResult = { rev: this.rev, value }
     return value
   }
@@ -178,6 +228,36 @@ export class FoldAdapter {
     return seqs
   }
 
+  /** Fold one command lifecycle event into its node (run mints, done settles in place; done-only soft-falls). */
+  private indexCommand(event: SessionEvent): void {
+    // Log-only plugin events: the host-side dsh-commands declaration cannot
+    // enter the client program, so this wire consumer narrows structurally
+    // (the same posture as tool/code-dispatch in session.ts).
+    if ((event.type as string) === 'command/run') {
+      const data = event.data as unknown as { commandId: CommandId; name: string; args: string }
+      this.commandIdx.set(data.commandId, {
+        kind: 'command', seq: event.seq, time: event.time,
+        commandId: data.commandId, name: data.name, args: data.args, outcome: null,
+      })
+      return
+    }
+    if ((event.type as string) !== 'command/done') return
+    const data = event.data as unknown as { commandId: CommandId; kind: 'success' | 'error'; text?: string }
+    const run = this.commandIdx.get(data.commandId)
+    const outcome = { kind: data.kind, ...data.text === undefined ? {} : { text: data.text } }
+    if (run === undefined) {
+      // Cross-window cut: the run page fell out of the window — build the
+      // node from the done alone (same soft-fall as a call-less tool result).
+      this.commandIdx.set(data.commandId, {
+        kind: 'command', seq: event.seq, time: event.time,
+        commandId: data.commandId, name: null, args: null, outcome,
+      })
+      return
+    }
+    // Settle in place: a fresh node object (published references stay immutable).
+    this.commandIdx.set(data.commandId, { ...run, outcome })
+  }
+
   private indexCall(event: SessionEvent, view?: ToolEventView): void {
     if (event.type === 'tool/result') {
       if (view?.for === 'result') this.resultViews.set(event.seq, view.view)
@@ -186,6 +266,7 @@ export class FoldAdapter {
     if (event.type !== 'tool/call') return
     this.callIdx.set(String(event.data.callId), {
       name: event.data.name, argsRaw: event.data.arguments, turn: event.data.turn, step: event.data.step,
+      time: event.time,
       callView: view?.for === 'call' ? view.view : null,
     })
     // No backfill into already-materialized tool-result nodes for this callId

packages/client/runtime/src/client/sessions/lineage.ts

@@ -1,14 +1,22 @@
 // flattenLineage: summaries -> flat list with lineage indentation (pure function).
-// Roots sort by updatedAt desc, DFS expansion with children in the same order; orphaned lineage
-// degrades to root level; cycles fail soft and emit as roots.
+// The input order is authoritative; lineage only makes each child adjacent to its parent.
+// Orphaned lineage degrades to root level; cycles fail soft and emit as roots.
 
 import type { SessionId, SessionSummary } from '@deepseek-ai/dsh-client-connection/client'
 
+/** Host list summary enriched with the latest mux-projected durable title. */
+export interface TitledSessionSummary extends SessionSummary {
+  title?: string
+}
+
 /** One flattened session-list row (summary + lineage indent depth). */
 export interface SessionListEntry {
   sessionId: SessionId
+  title?: string
   updatedAt: number
   running: boolean
+  /** Empty-log bit mirrored from the summary; lists hide blank sessions (filtering stays with the consumer). */
+  blank: boolean
   parentSessionId?: SessionId
   cwd?: string
   /** Lineage indent depth: root = 0; the UI just multiplies by the indent width. */
@@ -16,17 +24,18 @@ export interface SessionListEntry {
 }
 
 /**
- * summaries -> flat list with lineage indentation (pure; roots by updatedAt
- * desc, DFS children in the same order, orphans degrade to roots).
+ * Summaries -> flat list with lineage indentation. Root and sibling order
+ * follows the established input order; this projection never re-sorts a
+ * hydrated list from mutable timestamps.
  * @param summaries - the host's session.list items.
  * @returns display rows in render order.
  */
-export function flattenLineage(summaries: readonly SessionSummary[]): SessionListEntry[] {
-  const byId = new Map<SessionId, SessionSummary>()
+export function flattenLineage(summaries: readonly TitledSessionSummary[]): SessionListEntry[] {
+  const byId = new Map<SessionId, TitledSessionSummary>()
   for (const s of summaries) byId.set(s.sessionId, s)
 
-  const children = new Map<SessionId, SessionSummary[]>()
-  const roots: SessionSummary[] = []
+  const children = new Map<SessionId, TitledSessionSummary[]>()
+  const roots: TitledSessionSummary[] = []
   for (const s of summaries) {
     if (s.parentSessionId !== undefined && byId.has(s.parentSessionId)) {
       const list = children.get(s.parentSessionId) ?? []
@@ -37,12 +46,9 @@ export function flattenLineage(summaries: readonly SessionSummary[]): SessionLis
     }
   }
 
-  const byUpdatedDesc = (a: SessionSummary, b: SessionSummary): number => b.updatedAt - a.updatedAt
-  roots.sort(byUpdatedDesc)
-
   const out: SessionListEntry[] = []
   const visited = new Set<SessionId>()
-  const walk = (s: SessionSummary, depth: number): void => {
+  const walk = (s: TitledSessionSummary, depth: number): void => {
     if (visited.has(s.sessionId)) {
       console.warn(`[web-runtime] lineage cycle at ${s.sessionId}; emitting as root`)
       return
@@ -51,7 +57,6 @@ export function flattenLineage(summaries: readonly SessionSummary[]): SessionLis
     out.push({ ...s, depth })
     const kids = children.get(s.sessionId)
     if (kids === undefined) return
-    kids.sort(byUpdatedDesc)
     for (const kid of kids) walk(kid, depth + 1)
   }
   for (const root of roots) walk(root, 0)

packages/client/runtime/src/client/sessions/manager.ts

@@ -2,23 +2,53 @@
 // dispatch entry + list state, constructed and held by SessionsService (one per client runtime).
 // List data never enters zustand; React connects via subscribe/getListSnapshot.
 
-import type { IApiClient, HostFrame, MuxFrame, RpcError, RpcRequest, RpcResult, SessionId, SessionSummary } from '@deepseek-ai/dsh-client-connection/client'
-import { transportError } from '@deepseek-ai/dsh-client-connection/client'
-import type { SessionListEntry } from './lineage.ts'
+import type { IApiClient, HostFrame, MuxFrame, RpcError, RpcRequest, RpcResult, SessionId, SessionSummary, WorkspaceId } from '@deepseek-ai/dsh-client-connection/client'
+// Value import from the inline-safe wire layer (not the connection plugin):
+// plugin-to-plugin value imports are a bundle purity error.
+import { transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
+import { mergeOrderedBaseline } from '../ordered-baseline.ts'
+import type { SessionListEntry, TitledSessionSummary } from './lineage.ts'
 import { flattenLineage } from './lineage.ts'
+// Type-only merge edge: the title domain's client-namespace outlet declares
+// the 'title' projection key this manager projects into list rows (and any
+// useProjection('title') consumer reads). Zero value imports by construction.
+import type {} from '@deepseek-ai/dsh-session-title/client'
 import { Notifier } from './notifier.ts'
+import { ProjectionValueStore } from './projection-store.ts'
 import { Session } from './session.ts'
 
+/**
+ * List arrival lifecycle, orthogonal to the pull-activity `state` axis:
+ * `pending` (no successful pull yet — an empty items array means "nothing
+ * arrived", not "nothing exists") → `ready` (at least one pull landed).
+ * Monotone: `ready` never steps back — later pull failures and reconnect
+ * re-pulls ride the `state`/`error` axis, which is where failure is modeled
+ * (no `error` phase here; that would duplicate `state`).
+ */
+export type SessionListPhase = 'pending' | 'ready'
+
 /** Immutable session-list snapshot for useSessionList. */
 export interface SessionListSnapshot {
   items: readonly SessionListEntry[]
+  /** Selected Session id (validated against items; masked to undefined while its session is off the list). */
+  current: SessionId | undefined
   state: 'idle' | 'loading' | 'error'
+  /** Arrival lifecycle (see {@link SessionListPhase}); `state` stays the pull-activity axis. */
+  phase: SessionListPhase
   error: RpcError | null
 }
 
+type SessionListMutation =
+  | { kind: 'upsert'; summary: SessionSummary }
+  | { kind: 'remove'; sessionId: SessionId }
+  | { kind: 'status'; sessionId: SessionId; running: boolean }
+  /** Local first-send flip: the sender clears blank without waiting for a host frame. */
+  | { kind: 'engaged'; sessionId: SessionId }
+
 /** Per-session cap for pre-instantiation approval/question buffering (low-frequency frames; a few dozen covers any real backlog). */
 const PENDING_BUFFER_CAP = 32
 
+
 /** Instance cluster + frame entry + the session list (see the web client architecture RFC). */
 export class SessionManager {
   private readonly sessions = new Map<SessionId, Session>()
@@ -27,10 +57,21 @@ export class SessionManager {
    *  drop-and-backfill path; replayed and cleared on instantiation. Bounded per session (these
    *  frames are low-frequency; overflow drops oldest) and dropped on session-removed (audit S7). */
   private readonly pendingBuffers = new Map<SessionId, RpcRequest<MuxFrame>[]>()
+  /** Per-session projection value stores, retained independently of instance arrival (the
+   *  title-snapshot precedent, generalized): push frames land here whether or not the Session
+   *  is instantiated (list rows read the 'title' key), and an instantiated Session adopts the
+   *  same store so history-baseline seeding and frames converge on one row set. */
+  private readonly projectionStores = new Map<SessionId, ProjectionValueStore>()
   private summaries: SessionSummary[] = []
   private listState: 'idle' | 'loading' | 'error' = 'idle'
+  /** Arrival phase; the pending → ready edge fires on the first successful pull (see SessionListPhase). */
+  private listPhase: SessionListPhase = 'pending'
   private listError: RpcError | null = null
   private listInflight: Promise<void> | null = null
+  /** Mutations arriving after a list request starts are replayed over its response. */
+  private listMutations: SessionListMutation[] | null = null
+
+  private selected: SessionId | undefined
 
   private listSnapshotCache: SessionListSnapshot
   /** Entry-identity cache (§C.2 reference stability): list rebuilds reuse the previous entry
@@ -42,12 +83,50 @@ export class SessionManager {
     this.listSnapshotCache = this.buildListSnapshot()
   })
 
-  constructor(private readonly api: IApiClient) {
+  /**
+   * @param api - shared wire client.
+   * @param restoredSelection - persisted real-Session selection candidate.
+   */
+  constructor(
+    private readonly api: IApiClient,
+    restoredSelection?: SessionId,
+  ) {
+    this.selected = restoredSelection
     this.listSnapshotCache = this.buildListSnapshot()
   }
 
+  // ---- Selection ----
+
+  /**
+   * Select a listed Session.
+   * @param sessionId - listed Session id.
+   */
+  select(sessionId: SessionId): void {
+    if (!this.summaries.some(summary => summary.sessionId === sessionId)) {
+      throw new Error(`sessions.select: unknown session ${sessionId}`)
+    }
+    this.selected = sessionId
+    this.notifier.notifyNow()
+  }
+
+  /** Clear the selection (the layout falls to the no-session view state). */
+  clearSelection(): void {
+    this.selected = undefined
+    this.notifier.notifyNow()
+  }
+
   // ---- Instance management ----
 
+  /**
+   * Drop a session instance (scope-prune companion, decision 12: instance
+   * and scope share one lifecycle). The host session log is the durable
+   * truth — a later get() lazily rebuilds and open() backfills history.
+   * @param sessionId - the session to drop.
+   */
+  drop(sessionId: SessionId): void {
+    this.sessions.delete(sessionId)
+  }
+
   /**
    * Lazy build: return the existing instance or construct one (no auto-open —
    * open is triggered by the container's select callback).
@@ -57,21 +136,53 @@ export class SessionManager {
   get(sessionId: SessionId): Session {
     let session = this.sessions.get(sessionId)
     if (session === undefined) {
-      session = new Session(sessionId, this.api)
+      session = this.createSession(sessionId)
       this.sessions.set(sessionId, session)
-      // Sync the running bit from the list snapshot into the new instance (consistency when the list precedes open).
-      const summary = this.summaries.find(s => s.sessionId === sessionId)
-      if (summary !== undefined) session.handleRunning(summary.running)
-      // Replay approval/question frames buffered before instantiation (rpcId verbatim, same semantics as the subscribed baseline replay).
+      // Replay approval/question/queued frames buffered before instantiation (rpcId
+      // verbatim, same semantics as the subscribed baseline replay). Replay happens
+      // BEFORE the running-bit sync: a not-running summary must sweep replayed queue
+      // rows the same way a live status flip would (their retirement events dropped
+      // while the session was uninstantiated).
       const buffered = this.pendingBuffers.get(sessionId)
       if (buffered !== undefined) {
         this.pendingBuffers.delete(sessionId)
         for (const envelope of buffered) session.handleMuxEnvelope(envelope.rpcId, envelope.payload)
       }
+      // Sync the running and blank bits from the list snapshot into the new
+      // instance (consistency when the list precedes open).
+      const summary = this.summaries.find(s => s.sessionId === sessionId)
+      if (summary !== undefined) {
+        session.handleBlank(summary.blank)
+        session.handleRunning(summary.running)
+      }
     }
     return session
   }
 
+  private createSession(sessionId: SessionId): Session {
+    return new Session(sessionId, this.api, {
+      // The sender's local first-send flip mirrors into the list row so the
+      // session surfaces (lists filter on blank) before any host frame lands.
+      onEngaged: (engaged) => {
+        this.recordMutation({ kind: 'engaged', sessionId: engaged.sessionId })
+      },
+      projections: this.projectionStore(sessionId),
+    })
+  }
+
+  /** Resident per-session projection store (create-on-demand; outlives instantiation). */
+  private projectionStore(sessionId: SessionId): ProjectionValueStore {
+    let store = this.projectionStores.get(sessionId)
+    if (store === undefined) {
+      store = new ProjectionValueStore()
+      // List rows project off store keys (title); any-key changes re-enter
+      // the manager's own batched rebuild channel.
+      store.subscribeAny(() => { this.notifier.markDirty() })
+      this.projectionStores.set(sessionId, store)
+    }
+    return store
+  }
+
   // ---- List surface ----
 
   /** Full refresh via session.list (single-flight: an in-flight call is reused). */
@@ -79,15 +190,28 @@ export class SessionManager {
     if (this.listInflight !== null) return this.listInflight
     this.listState = 'loading'
     this.listError = null
+    const established = this.summaries
+    const mutations: SessionListMutation[] = []
+    this.listMutations = mutations
     this.notifier.markDirty()
     this.listInflight = (async () => {
       try {
         const { result } = await this.api.sessions.list({})
         if (result.ok) {
-          this.summaries = result.value.items
+          let summaries = this.listPhase === 'pending'
+            ? result.value.items
+            : mergeOrderedBaseline(established, result.value.items, summary => summary.sessionId)
+          for (const mutation of mutations) summaries = applyMutation(summaries, mutation)
+          this.summaries = summaries
           this.listState = 'idle'
-          // Push running bits down to instantiated Sessions (the list is the authoritative summary source).
-          for (const s of this.summaries) this.sessions.get(s.sessionId)?.handleRunning(s.running)
+          this.listPhase = 'ready'
+          // Push running/blank bits down to instantiated Sessions (the list is the authoritative summary source).
+          for (const s of this.summaries) {
+            const session = this.sessions.get(s.sessionId)
+            if (session === undefined) continue
+            session.handleBlank(s.blank)
+            session.handleRunning(s.running)
+          }
         } else {
           this.listState = 'error'
           this.listError = result.error
@@ -98,6 +222,7 @@ export class SessionManager {
         /* v8 ignore next -- the `? null` arm is unreachable: transportError always returns ok:false. */
         this.listError = folded.ok ? null : folded.error
       } finally {
+        this.listMutations = null
         this.listInflight = null
         this.notifier.markDirty()
       }
@@ -107,19 +232,38 @@ export class SessionManager {
 
   /**
    * Contract session.create; on success merge into summaries immediately (no
-   * wait for the next refresh).
-   * @param cwd - optional working directory for the new session.
+   * wait for the next refresh). A created session is blank by definition
+   * (entity birth precedes the first message).
+   * @param opts - target workspace or working directory, plus an optional caller-owned id.
    * @returns the create result.
    */
-  async create(cwd?: string): Promise<RpcResult<{ sessionId: SessionId }>> {
+  async create(
+    opts: { workspaceId?: WorkspaceId; cwd?: string; sessionId?: SessionId } = {},
+  ): Promise<RpcResult<{ sessionId: SessionId }>> {
     try {
-      const { result } = await this.api.sessions.create(cwd === undefined ? {} : { cwd })
-      if (result.ok && !this.summaries.some(s => s.sessionId === result.value.sessionId)) {
-        this.summaries = [
-          { sessionId: result.value.sessionId, updatedAt: Date.now(), running: false, ...(cwd !== undefined ? { cwd } : {}) },
-          ...this.summaries,
-        ]
-        this.notifier.markDirty()
+      const shared = opts.sessionId === undefined ? {} : { sessionId: opts.sessionId }
+      const payload = opts.workspaceId !== undefined
+        ? { workspaceId: opts.workspaceId, ...shared }
+        : { ...(opts.cwd === undefined ? {} : { cwd: opts.cwd }), ...shared }
+      const { result } = await this.api.sessions.create(payload)
+      if (result.ok) {
+        this.recordMutation({ kind: 'upsert', summary: {
+          sessionId: result.value.sessionId, updatedAt: Date.now(), running: false, blank: true,
+          ...(opts.cwd !== undefined ? { cwd: opts.cwd } : {}),
+        } })
+      } else {
+        const publishedSessionId = workspaceAttachSessionId(result.error)
+        // Publication precedes attachment. The error's id is a real Session,
+        // so expose it immediately as Ungrouped while the caller keeps the
+        // prompt buffer and decides whether to retry attachment.
+        if (publishedSessionId !== undefined) {
+          this.recordMutation({ kind: 'upsert', summary: {
+            sessionId: publishedSessionId,
+            updatedAt: Date.now(),
+            running: false,
+            blank: true,
+          } })
+        }
       }
       return result
     } catch (error) {
@@ -127,6 +271,23 @@ export class SessionManager {
     }
   }
 
+  /**
+   * Insert-or-enrich a locally synthesized summary: a new id prepends; an
+   * existing entry only gains fields it lacks (the session-added frame and the
+   * create() echo race — whichever lands second must fill the placeholder's
+   * missing cwd/parentSessionId, never overwrite list-refresh data).
+   */
+  private mergeSummary(summary: SessionSummary): void {
+    this.recordMutation({ kind: 'upsert', summary })
+  }
+
+  /** Apply immediately and retain for replay when a list response is in flight. */
+  private recordMutation(mutation: SessionListMutation): void {
+    this.listMutations?.push(mutation)
+    this.summaries = applyMutation(this.summaries, mutation)
+    this.notifier.markDirty()
+  }
+
   // ---- Subscription surface (for useSessionList) ----
 
   /**
@@ -158,15 +319,45 @@ export class SessionManager {
   handleMuxEnvelope(envelope: RpcRequest<MuxFrame>): void {
     const frame = envelope.payload
     if (frame.type === 'stream/error') return // Controller already treats this as stream failure
+    if (frame.type === 'session/projection') {
+      // Finished host-computed value: land it in the resident store whether or
+      // not the Session is instantiated (list rows read the 'title' key). The
+      // synchronous markDirty keeps the list snapshot same-tick fresh (the
+      // store's own any-key channel is microtask-batched).
+      this.projectionStore(frame.sessionId).apply(frame.key, frame.value, frame.seq)
+      this.notifier.markDirty()
+      return
+    }
+    if (frame.type === 'session/subscribed') {
+      // Rows past the host's durable baseline rode state a restart lost; drop
+      // them so last-wins cannot pin a phantom value over recomputed truth.
+      this.projectionStores.get(frame.sessionId)?.truncate(frame.lastSeq)
+      this.notifier.markDirty()
+      // New mux-generation baseline: buffered session/queued frames belong to
+      // the previous generation and the host is about to resend the live
+      // snapshot — drop them, or every reconnect appends a duplicate batch
+      // (and enough reconnects push real approval/question frames past the
+      // cap). Same re-baseline signal Session uses for its own mirror.
+      const buffered = this.pendingBuffers.get(frame.sessionId)
+      if (buffered !== undefined) {
+        const kept = buffered.filter(item => item.payload.type !== 'session/queued')
+        if (kept.length !== buffered.length) {
+          if (kept.length === 0) this.pendingBuffers.delete(frame.sessionId)
+          else this.pendingBuffers.set(frame.sessionId, kept)
+        }
+      }
+    }
     const session = this.sessions.get(frame.sessionId)
     if (session === undefined) {
-      // Approval/question frames never hit history: buffer for replay on instantiation;
-      // everything else drops (not instantiated — history fully backfills on open).
+      // Approval/question/queued frames never hit history: buffer for replay on
+      // instantiation; everything else drops (not instantiated — history fully
+      // backfills on open).
       switch (frame.type) {
         case 'approval/requested':
         case 'approval/resolved':
         case 'question/requested':
-        case 'question/resolved': {
+        case 'question/resolved':
+        case 'session/queued': {
           const buffer = this.pendingBuffers.get(frame.sessionId) ?? []
           buffer.push(envelope)
           if (buffer.length > PENDING_BUFFER_CAP) buffer.splice(0, buffer.length - PENDING_BUFFER_CAP)
@@ -188,30 +379,24 @@ export class SessionManager {
     const frame = envelope.payload
     switch (frame.type) {
       case 'host/session-added': {
-        if (!this.summaries.some(s => s.sessionId === frame.sessionId)) {
-          this.summaries = [
-            {
-              sessionId: frame.sessionId, updatedAt: Date.now(), running: false,
-              ...(frame.parentSessionId !== undefined ? { parentSessionId: frame.parentSessionId } : {}),
-            },
-            ...this.summaries,
-          ]
-          this.notifier.markDirty()
-        }
+        this.mergeSummary({
+          sessionId: frame.sessionId, updatedAt: Date.now(), running: false, blank: frame.blank,
+          ...(frame.parentSessionId !== undefined ? { parentSessionId: frame.parentSessionId } : {}),
+          ...(frame.cwd !== undefined ? { cwd: frame.cwd } : {}),
+        })
+        this.sessions.get(frame.sessionId)?.handleBlank(frame.blank)
         return
       }
       case 'host/session-removed': {
-        this.summaries = this.summaries.filter(s => s.sessionId !== frame.sessionId)
+        this.recordMutation({ kind: 'remove', sessionId: frame.sessionId })
         this.sessions.get(frame.sessionId)?.handleRemoved() // instance survives (resident-instance rule), only flagged in the snapshot
         this.pendingBuffers.delete(frame.sessionId) // a removed session's buffered frames must not replay on a future instantiation
-        this.notifier.markDirty()
+        this.projectionStores.delete(frame.sessionId) // removed sessions drop their projection rows with the instance
         return
       }
       case 'host/session-status': {
-        this.summaries = this.summaries.map(s =>
-          s.sessionId === frame.sessionId && s.running !== frame.running ? { ...s, running: frame.running } : s)
+        this.recordMutation({ kind: 'status', sessionId: frame.sessionId, running: frame.running })
         this.sessions.get(frame.sessionId)?.handleRunning(frame.running)
-        this.notifier.markDirty()
         return
       }
       case 'host/agent-error': {
@@ -223,19 +408,29 @@ export class SessionManager {
     }
   }
 
-  /** After each connection generation (first connect included): refresh the list + resync opened instances (reconnect = rebuild). */
+  /** After each connection generation: refresh the session baseline and rebuild opened windows. */
   handleConnected(): void {
     void this.refreshList()
     for (const session of this.sessions.values()) void session.resync()
   }
 
   private buildListSnapshot(): SessionListSnapshot {
-    const fresh = flattenLineage(this.summaries)
+    const merged: TitledSessionSummary[] = this.summaries.map((summary) => {
+      // List rows read the generic 'title' projection key (host-computed unit
+      // value; the bespoke session/title frame is retired).
+      const title = this.projectionStores.get(summary.sessionId)?.get('title')
+      return typeof title === 'string' && title !== ''
+        ? { ...summary, title }
+        : summary
+    })
+    const fresh = flattenLineage(merged)
     const items = fresh.map((entry) => {
       const prev = this.entryCache.get(entry.sessionId)
       if (
         prev !== undefined && prev.updatedAt === entry.updatedAt && prev.running === entry.running
-        && prev.parentSessionId === entry.parentSessionId && prev.cwd === entry.cwd && prev.depth === entry.depth
+        && prev.blank === entry.blank
+        && prev.parentSessionId === entry.parentSessionId && prev.cwd === entry.cwd
+        && prev.title === entry.title && prev.depth === entry.depth
       ) return prev
       this.entryCache.set(entry.sessionId, entry)
       return entry
@@ -245,6 +440,57 @@ export class SessionManager {
     }
     const sameOrder = items.length === this.itemsCache.length && items.every((e, i) => e === this.itemsCache[i])
     if (!sameOrder) this.itemsCache = items
-    return { items: this.itemsCache, state: this.listState, error: this.listError }
+    const selected = this.selected
+    const current = selected !== undefined && items.some(item => item.sessionId === selected)
+      ? selected
+      : undefined
+    return {
+      items: this.itemsCache,
+      current,
+      state: this.listState,
+      phase: this.listPhase,
+      error: this.listError,
+    }
   }
 }
+
+/** Apply one list mutation without deriving display order. */
+function applyMutation(summaries: readonly SessionSummary[], mutation: SessionListMutation): SessionSummary[] {
+  switch (mutation.kind) {
+    case 'upsert': {
+      const existing = summaries.find(summary => summary.sessionId === mutation.summary.sessionId)
+      if (existing === undefined) return [mutation.summary, ...summaries]
+      const filled: SessionSummary = {
+        ...existing,
+        // Blank only lowers: a stale true (session-added racing the local
+        // first send) never re-hides an already-surfaced session.
+        blank: existing.blank && mutation.summary.blank,
+        ...(existing.cwd === undefined && mutation.summary.cwd !== undefined ? { cwd: mutation.summary.cwd } : {}),
+        ...(existing.parentSessionId === undefined && mutation.summary.parentSessionId !== undefined
+          ? { parentSessionId: mutation.summary.parentSessionId } : {}),
+      }
+      if (filled.cwd === existing.cwd && filled.parentSessionId === existing.parentSessionId
+        && filled.blank === existing.blank) return [...summaries]
+      return summaries.map(summary => summary.sessionId === mutation.summary.sessionId ? filled : summary)
+    }
+    case 'remove':
+      return summaries.filter(summary => summary.sessionId !== mutation.sessionId)
+    case 'status':
+      // running:true doubles as the cross-端 blank flip (a blank session
+      // never runs, so the first running frame proves a message landed).
+      return summaries.map(summary => summary.sessionId === mutation.sessionId
+        && (summary.running !== mutation.running || (mutation.running && summary.blank))
+        ? { ...summary, running: mutation.running, blank: summary.blank && !mutation.running }
+        : summary)
+    case 'engaged':
+      return summaries.map(summary => summary.sessionId === mutation.sessionId && summary.blank
+        ? { ...summary, blank: false }
+        : summary)
+  }
+}
+
+/** Temporary source-plane bridge while the Host contract and client project build independently. */
+function workspaceAttachSessionId(error: RpcError): SessionId | undefined {
+  const candidate = error as unknown as { code: string; details: { sessionId?: SessionId } }
+  return candidate.code === 'workspace-attach-failed' ? candidate.details.sessionId : undefined
+}

packages/client/runtime/src/client/sessions/notifier.ts

@@ -3,11 +3,17 @@
 // the flush rebuilds the snapshot cache BEFORE notifying (useSyncExternalStore requires a stable
 // getSnapshot reference). With no listeners the rebuild is skipped and only the dirty bit is set
 // (keeps frame storms cheap); the next getSnapshot rebuilds lazily.
+//
+// Freshness and notification are SEPARATE bits: a pull (ensureFresh) between
+// markDirty and the scheduled flush rebuilds the snapshot but must not
+// swallow the notification — push subscribers (object-layer watchers) would
+// otherwise starve whenever any reader pulls first.
 
 /** Subscription + microtask-batched notification primitive (shared by Session and SessionManager). */
 export class Notifier {
   private listeners = new Set<() => void>()
   private dirty = false
+  private notifyPending = false
   private scheduled = false
 
   /** @param rebuild - snapshot rebuild function injected by the owner (writes the owner's snapshotCache). */
@@ -28,14 +34,18 @@ export class Notifier {
   /** State-change entry: mark dirty and schedule the batched flush. */
   markDirty(): void {
     this.dirty = true
+    this.notifyPending = true
     if (this.scheduled) return
     this.scheduled = true
     queueMicrotask(() => {
       this.scheduled = false
-      if (!this.dirty) return
-      if (this.listeners.size === 0) return // lazy: no subscribers, keep dirty for the next getSnapshot
-      this.dirty = false
-      this.rebuild()
+      if (!this.notifyPending) return
+      if (this.listeners.size === 0) return // lazy: no subscribers; dirty (if still set) rebuilds on next getSnapshot
+      this.notifyPending = false
+      if (this.dirty) {
+        this.dirty = false
+        this.rebuild()
+      }
       for (const listener of this.listeners) listener()
     })
   }
@@ -46,13 +56,18 @@ export class Notifier {
    */
   notifyNow(): void {
     this.dirty = true
+    this.notifyPending = true
     if (this.listeners.size === 0) return // lazy: same as markDirty, next getSnapshot rebuilds
+    this.notifyPending = false
     this.dirty = false
     this.rebuild()
     for (const listener of this.listeners) listener()
   }
 
-  /** Pre-getSnapshot check: rebuild synchronously when dirty (read path before first subscribe / while unobserved). */
+  /**
+   * Pre-getSnapshot check: rebuild synchronously when dirty (read path
+   * before first subscribe / while unobserved). Notification stays pending.
+   */
   ensureFresh(): void {
     if (!this.dirty) return
     this.dirty = false

packages/client/runtime/src/client/sessions/pending.ts

@@ -0,0 +1,79 @@
+// PendingWait: the carrier-protocol half of a pending host interaction. The runtime owns only
+// envelope knowledge (rpcId backfill into a client-response); domain result encoding belongs to
+// the interaction's consumer package.
+
+import type {
+  ClientResponse, MuxFrame, RpcId, RpcReceipt, SessionId,
+} from '@deepseek-ai/dsh-client-connection/client'
+
+/** Kind-keyed payload map: the requested frame's domain fields (envelope fields stripped). */
+export interface PendingPayloads {
+  approval: Omit<Extract<MuxFrame, { type: 'approval/requested' }>, 'type' | 'sessionId'>
+  question: Omit<Extract<MuxFrame, { type: 'question/requested' }>, 'type' | 'sessionId'>
+}
+
+/** Pending-interaction discriminant (the keys of PendingPayloads). */
+export type PendingKind = keyof PendingPayloads
+
+/** Kind-discriminated union of concrete waits: narrowing on `kind` types `payload`. */
+export type PendingInteraction = { [K in PendingKind]: PendingWait<K> }[PendingKind]
+
+/** Key prefixes, one per kind (the key doubles as the Session pending-map key). */
+const KEY_PREFIX: Record<PendingKind, string> = { approval: 'a', question: 'q' }
+
+/**
+ * One pending host-owned interaction wait: an immutable render face
+ * (kind/key/sessionId/payload) plus the response carrier. respond() backfills
+ * the requested frame's rpcId into a client-response envelope — no consumer
+ * ever sees the raw rpcId. Settlement is expressed only by pending-list
+ * membership (the settled flag is a fail-loud guard, not a render input).
+ */
+export class PendingWait<K extends PendingKind = PendingKind> {
+  /** Interaction kind (union discriminant). */
+  readonly kind: K
+  /** Opaque render identity, `<prefix>:<rpcId>` — stable across baseline replay, usable as a React key. */
+  readonly key: string
+  /** Owning session. */
+  readonly sessionId: SessionId
+  /** The requested frame's domain fields, verbatim. */
+  readonly payload: PendingPayloads[K]
+  #settled = false
+  readonly #rpcId: RpcId
+  readonly #respond: (message: ClientResponse) => Promise<RpcReceipt>
+
+  /**
+   * Minted by Session on a requested frame (public construction is the test-fixture path).
+   * @param kind - interaction kind.
+   * @param rpcId - the requested frame's stable envelope id (kept private; respond echoes it).
+   * @param sessionId - owning session.
+   * @param payload - the requested frame's domain fields.
+   * @param respond - the client-response carrier (api.respond).
+   */
+  constructor(
+    kind: K, rpcId: RpcId, sessionId: SessionId, payload: PendingPayloads[K],
+    respond: (message: ClientResponse) => Promise<RpcReceipt>,
+  ) {
+    this.kind = kind
+    this.key = `${KEY_PREFIX[kind]}:${rpcId}`
+    this.sessionId = sessionId
+    this.payload = payload
+    this.#rpcId = rpcId
+    this.#respond = respond
+  }
+
+  /**
+   * Send a result for this wait: wraps it into the client-response envelope
+   * with the rpcId backfilled. Throws synchronously once settled.
+   * @param result - the result shell (ok value / error envelope), domain-encoded by the caller.
+   * @returns the carrier receipt.
+   */
+  respond(result: ClientResponse['result']): Promise<RpcReceipt> {
+    if (this.#settled) throw new Error(`pending wait ${this.key} is already settled`)
+    return this.#respond({ type: 'client-response', rpcId: this.#rpcId, result })
+  }
+
+  /** Session-only settlement mark (the authoritative resolved frame arrived); respond() throws afterwards. */
+  markSettled(): void {
+    this.#settled = true
+  }
+}

packages/client/runtime/src/client/sessions/projection-store.ts

@@ -0,0 +1,183 @@
+/**
+ * Generic per-session projection value store (session-projection RFC, push
+ * model): the host is the only computation site; the client holds finished
+ * whole values per key — `key → { value, seq }` — seeded by the history tail
+ * page's projections block and updated by `session/projection` push frames,
+ * under the single rule **higher seq wins**. No client-side domain folding
+ * exists: a domain ships projection support with zero client code. Per-key
+ * bare observable faces feed `useProjection` (web-react binds them).
+ */
+import type { SessionProjectionMap } from '@deepseek-ai/dsh-session-projection/types'
+import type { ObservableSnapshot } from '../contract/store.ts'
+import { Notifier } from './notifier.ts'
+
+// The single projection type table, typed end to end (host unit, wire block,
+// client store, React hook) — the interface package's pure-type outlet
+// (`/types`, zero imports), never the package root: the root's dsh-agent →
+// dsh-session chain would drag the host `Context.sessions` merge into the
+// client program (one program must not hold both sides). No second
+// client-side "views" table (user ruling, RFC Alternatives).
+export type { SessionProjectionMap } from '@deepseek-ai/dsh-session-projection/types'
+
+/**
+ * The fifth framework hook seat (session-projection RFC): key-addressed
+ * projection reader delivered through the standard kit. `undefined` uniformly
+ * means capability absent — host unit unmounted, or no baseline/frame has
+ * carried the key yet. The selector overload mirrors useSession (per-key uSES
+ * binding; reference stability holds because a key's value reference changes
+ * only when a frame or baseline lands).
+ */
+export type UseProjection = {
+  <K extends Extract<keyof SessionProjectionMap, string>>(key: K): SessionProjectionMap[K] | undefined
+  <K extends Extract<keyof SessionProjectionMap, string>, S>(
+    key: K,
+    selector: (value: SessionProjectionMap[K] | undefined) => S,
+    eq?: (a: S, b: S) => boolean,
+  ): S
+}
+
+/**
+ * Tail-page projections baseline — structurally identical to the wire's
+ * `SessionProjectionsBlock` (apiproxy api layer), restated here so the
+ * React-free store depends only on the type table, not the wire package's
+ * response vocabulary.
+ */
+export interface ProjectionsBaseline {
+  /** The consistent-cut seq (equals the window tail seq by construction). */
+  asOfSeq: number
+  /** Whole current values by key; a registered key absent here means the capability is absent. */
+  values: Partial<SessionProjectionMap>
+}
+
+/** One key's row: the latest finished value and the seq it is consistent with. */
+interface Row {
+  value: unknown
+  seq: number
+}
+
+/** Per-key notification channel: the bare face plus its batching notifier. */
+interface Channel {
+  face: ObservableSnapshot<unknown>
+  notifier: Notifier
+}
+
+/**
+ * One session's projection values. Framework semantics, uniform across every
+ * key: a baseline seeds rows at its cut, a push frame updates one row, and in
+ * both paths a lower-or-equal seq loses — a replayed frame cannot regress a
+ * value, a stale baseline cannot overwrite a newer frame. A key the store has
+ * never seen reads `undefined` (capability absent). Faces are identity-stable
+ * per key (create-on-demand, cached) so the React side binds each exactly
+ * once; the store-level channel (`subscribeAny`) serves coarse consumers (the
+ * manager's list projection reads the `title` key).
+ */
+export class ProjectionValueStore {
+  private readonly rows = new Map<string, Row>()
+  private readonly channels = new Map<string, Channel>()
+  /** Coarse any-key channel (no snapshot cache to rebuild: reads hit rows directly). */
+  private readonly anyNotifier = new Notifier(() => {})
+
+  /**
+   * Key-addressed bare observable face (the useProjection resolution path).
+   * Always defined — absence is an `undefined` snapshot, never a missing
+   * face, so a component may subscribe before the key ever carries a value.
+   * @param key - projection key.
+   * @returns the identity-stable face for this key.
+   */
+  faceOf(key: string): ObservableSnapshot<unknown> {
+    return this.channel(key).face
+  }
+
+  /**
+   * Current whole value for a key (erased framework read; typed reads go
+   * through `useProjection`'s map lookup).
+   * @param key - projection key.
+   * @returns the value, or undefined while the key is absent.
+   */
+  get(key: string): unknown {
+    return this.rows.get(key)?.value
+  }
+
+  /**
+   * Subscribe to any-key changes (microtask-batched) — the manager's list
+   * rebuild channel.
+   * @param listener - change callback.
+   * @returns the unsubscribe function.
+   */
+  subscribeAny(listener: () => void): () => void {
+    return this.anyNotifier.subscribe(listener)
+  }
+
+  /**
+   * Apply one finished value (the `session/projection` push-frame path).
+   * @param key - projection key.
+   * @param value - whole value computed by the host unit.
+   * @param seq - the unit's watermark at emission.
+   */
+  apply(key: string, value: unknown, seq: number): void {
+    const row = this.rows.get(key)
+    if (row !== undefined && seq <= row.seq) return // higher seq wins; replays and stale frames drop
+    this.rows.set(key, { value, seq })
+    this.changed(key)
+  }
+
+  /**
+   * Seed from a history tail page's projections block: every carried key
+   * lands under the same seq rule as frames; a key the block omits is
+   * capability-absent as of the cut — its row clears unless a newer frame
+   * already superseded the cut (a stale baseline can neither overwrite nor
+   * clear newer values).
+   * @param baseline - the response's projections block.
+   */
+  seed(baseline: ProjectionsBaseline): void {
+    // Erased walk: the framework crosses the open key space; per-key typing
+    // is re-established at the consumer (useProjection's map lookup).
+    const values = baseline.values as Record<string, unknown>
+    for (const key of Object.keys(values)) this.apply(key, values[key], baseline.asOfSeq)
+    for (const [key, row] of this.rows) {
+      if (Object.hasOwn(values, key)) continue
+      if (row.seq > baseline.asOfSeq) continue
+      this.rows.delete(key)
+      this.changed(key)
+    }
+  }
+
+  /**
+   * Drop rows past a mux-generation baseline (`session/subscribed.lastSeq`):
+   * a row claiming knowledge beyond the host's own durable baseline rode
+   * state a restart lost — under last-wins it would wrongly outrank the
+   * host's recomputed (lower-seq) values forever. Durable replay and the next
+   * baseline re-seed whatever truly survived (the title-snapshot precedent,
+   * generalized).
+   * @param lastSeq - the subscribed frame's durable baseline seq.
+   */
+  truncate(lastSeq: number): void {
+    for (const [key, row] of this.rows) {
+      if (row.seq <= lastSeq) continue
+      this.rows.delete(key)
+      this.changed(key)
+    }
+  }
+
+  private changed(key: string): void {
+    this.channels.get(key)?.notifier.markDirty()
+    this.anyNotifier.markDirty()
+  }
+
+  private channel(key: string): Channel {
+    let channel = this.channels.get(key)
+    if (channel === undefined) {
+      // The notifier only batches (no snapshot cache to rebuild: faces read rows directly).
+      const notifier = new Notifier(() => {})
+      channel = {
+        notifier,
+        face: {
+          getSnapshot: () => this.rows.get(key)?.value,
+          subscribe: listener => notifier.subscribe(listener),
+        },
+      }
+      this.channels.set(key, channel)
+    }
+    return channel
+  }
+}

packages/client/runtime/src/client/sessions/service.ts

@@ -1,35 +1,80 @@
 /**
  * SessionsService: root sessions service — list snapshot store (manager
- * projection), session scope tree (mintScope pattern: no-op plugin Fiber +
- * ctx.extend scope tag), stable SessionBinding cache, ancestry walk.
+ * projection; carries `current`, the persisted selection every
+ * session-scoped surface keys off — migrated here from ui-layout per the
+ * slot-parity design), Agent scope tree (mintScope pattern: no-op plugin
+ * Fiber + ctx.extend scope tag; one scope per session, agent id === session
+ * id), stable SessionBinding cache, ancestry walk.
  *
- * Scope lifecycle is watch-driven: a scope is minted lazily on first
- * resolution; a session leaving the list tears its scope down only when
- * nobody is watching it. "Watched" is approximated as the most recently
- * resolved binding id — SessionProvider re-resolves on every selection
- * change (keyed remount), so a switch away always re-evaluates the deferred
- * teardown; a host-side death without list removal keeps the scope (frozen
- * read-only view).
+ * Scope lifecycle is stage-driven: a scope is minted lazily on first
+ * resolution (pure — resolution has no side effects and is render-safe);
+ * the event window and deferred teardown key off the STAGED session, which
+ * follows `list.current` exactly. Staging is the open signal: the window
+ * opens ⟺ the session is on stage (today the stage is `current`; the staged
+ * state can widen to a multi-pane list later). A session leaving the list
+ * tears its scope down immediately unless it is the staged one, whose scope
+ * survives frozen (read-only view) until the stage moves on.
  */
 import type { Context, Fiber } from 'cordis'
-import type { IApiClient, SessionId } from '@deepseek-ai/dsh-client-connection/client'
-import type { SnapshotStore } from '@deepseek-ai/dsh-client-web-react'
-import { createSnapshotStore } from '@deepseek-ai/dsh-client-web-react'
+import type { IApiClient, RpcError, SessionId, WorkspaceId } from '@deepseek-ai/dsh-client-connection/client'
+import type {
+  HostObservable, SessionMaybeProvideInfo, SessionProvideInfo,
+} from '@deepseek-ai/dsh-client-ui-slots'
+import type { SnapshotStore } from '../contract/store.ts'
+import { createSnapshotStore } from '../contract/store.ts'
+import { createScope, scopeOf as scopeTagOf } from '../agents/scope.ts'
 import { SessionManager } from './manager.ts'
+import type { SessionListPhase } from './manager.ts'
 import type { Session } from './session.ts'
 
 /** Session list row projected from the host list RPC plus live stream increments. */
 export interface SessionSummary {
   id: SessionId
-  title: string
+  /** Latest durable log-backed title, absent until the host projects one. */
+  title?: string
+  /** Human-facing label: durable title, project basename, then session id. */
+  displayTitle: string
   cwd?: string
   parentId?: SessionId
   running: boolean
+  /**
+   * Empty-log bit (host summary derivation mirror). New Session reuses a blank
+   * one targeting the same workspace. Filtering stays with the consumer: the
+   * store carries every row, while the Workspace browser shows only the
+   * selected blank entry.
+   */
+  blank: boolean
   updatedAt: number
 }
 
-/** Session list store shape. */
-export interface SessionListState { ids: SessionId[]; byId: Record<SessionId, SessionSummary> }
+/**
+ * Session list store shape. `current` rides the same snapshot (arbitrated:
+ * the single useSessions standard hook reads list and selection together —
+ * sidebar highlighting and SessionProvider share one fact source).
+ */
+export interface SessionListState {
+  ids: SessionId[]
+  byId: Record<SessionId, SessionSummary>
+  current: SessionId | undefined
+  /** Arrival lifecycle projected 1:1 from the manager snapshot (see SessionListPhase): empty-with-ready means "truly no sessions". */
+  phase: SessionListPhase
+}
+
+/** Structured session-create failure. */
+export class SessionCreateError extends Error {
+  override readonly name = 'SessionCreateError'
+
+  /**
+   * @param rpcError - Host business or folded transport error.
+   * @param requestedSessionId - caller-preallocated id used for later stream/list reconciliation.
+   */
+  constructor(
+    readonly rpcError: RpcError,
+    readonly requestedSessionId: SessionId | undefined,
+  ) {
+    super(`session create failed: ${rpcError.code}: ${rpcError.message}`)
+  }
+}
 
 /** Session assembly handle for SessionProvider/inject factories (identity-stable per session). */
 export interface SessionBinding {
@@ -38,29 +83,34 @@ export interface SessionBinding {
   readonly ctx: Context
 }
 
-/** Scope tag key (client counterpart of the host dsh-scope pattern). */
-const kScope = Symbol('dsh.client.scope')
+// Scope primitives live in ../agents/scope.ts (the client mirror of host
+// dsh-scope, keyed by Agent identity); re-exported here so existing
+// consumers keep their import site.
+export { scopeOf } from '../agents/scope.ts'
 
 /**
- * Read the session scope tag off a context.
- * @param ctx - any client context.
- * @returns the session id, or undefined on root contexts.
+ * Workspace display title of a session cwd: the path's last non-empty
+ * segment (both separators accepted; trailing separators ignored), or ''
+ * for separator-only paths — callers own their fallback (session id, raw
+ * cwd, default-directory copy). The repo-wide single basename derivation —
+ * every surface naming a workspace (picker rows, toggle labels, list titles)
+ * calls this instead of re-splitting paths.
+ * @param cwd - workspace directory path.
+ * @returns basename title, or '' when no non-empty segment exists.
  */
-export function scopeOf(ctx: Context): SessionId | undefined {
-  return (ctx as Context & { [kScope]?: SessionId })[kScope]
+export function workspaceTitleOf(cwd: string): string {
+  return cwd.replace(/[/\\]+$/, '').split(/[/\\]/).pop() ?? ''
 }
 
-/** Shared no-op plugin backing each session scope fiber. */
-function sessionScope(): void {}
-
 /**
- * Display title projection. The wire summary carries no title yet (P-I
- * ledger): the project directory's basename stands in, then the raw id.
+ * Display title projection: durable title, project directory basename, then
+ * the raw id.
  */
-function titleOf(cwd: string | undefined, id: SessionId): string {
+function displayTitleOf(title: string | undefined, cwd: string | undefined, id: SessionId): string {
+  if (title !== undefined) return title
   if (cwd !== undefined && cwd !== '') {
-    const base = cwd.replace(/[/\\]+$/, '').split(/[/\\]/).pop()
-    if (base !== undefined && base !== '') return base
+    const base = workspaceTitleOf(cwd)
+    if (base !== '') return base
   }
   return id
 }
@@ -69,19 +119,73 @@ interface ScopeRecord {
   fiber: Fiber
   ctx: Context
   binding: SessionBinding
+  /** Render-layer standard-props bundle (identity-stable per scope; the renderer's per-info caches key off it). */
+  provideInfo: SessionProvideInfo
 }
 
-/** Root sessions service: list store, object-layer manager, scope tree, bindings, ancestry. */
+/** One plugin's per-session standard-props contribution (see {@link SessionsService.provide}). */
+export interface SessionProvideContribution {
+  /** Bare observable sources, keyed by hook base name ('input' → useInput). */
+  hooks?: Record<string, HostObservable<unknown>>
+  /** Stable plain members (action callbacks etc.), spread into standard props verbatim. */
+  props?: Record<string, unknown>
+}
+
+/**
+ * Static declaration plus per-session resolver for one standard-kit
+ * contribution. The declared names let the renderer construct the same hook
+ * and prop surface while no session is current.
+ */
+export interface SessionProvideDescriptor {
+  /** Hook base names (`input` becomes `useInput`). */
+  hooks?: readonly string[]
+  /** Plain standard-prop names. */
+  props?: readonly string[]
+  /** Resolve every declared member for one definite session. */
+  resolve(binding: SessionBinding): SessionProvideContribution
+}
+
+/** Root sessions service: list store, current selection, object-layer manager, scope tree, bindings, ancestry. */
 export class SessionsService {
-  /** List snapshot store (list RPC + host stream increments; re-pulled on reconnect). */
+  /** List snapshot store (list RPC + host stream increments; re-pulled on reconnect) — the useSessions standard feed, current included. */
   readonly list: SnapshotStore<SessionListState>
-  /** The object-layer instance cluster and frame dispatch entry (wired to the connection by the runtime apply). */
-  readonly manager: SessionManager
+  /** The object-layer instance cluster and frame dispatch entry. */
+  private readonly manager: SessionManager
+  /**
+   * Atomic current-session provide projection: selection changes and
+   * provider-roster changes publish through this one source (the renderer
+   * host's `sessions.provide` feed), so a roster change under a stable
+   * current id republishes the bundle instead of stranding mounted entries.
+   */
+  readonly currentProvideInfo: HostObservable<SessionMaybeProvideInfo>
+
+  /**
+   * Persisted selection cell (the durable half of `list.current`). Private on
+   * purpose: reads go through the list snapshot; writes through {@link
+   * SessionsService.open} / {@link SessionsService.clear}. Projection
+   * validates it against the live list instead of destructively pruning, so a
+   * selection survives transient list states (reconnect re-pull) and
+   * resurfaces when its session returns.
+   */
+  private readonly selection: SnapshotStore<{ sessionId?: SessionId }>
 
   private readonly scopes = new Map<SessionId, ScopeRecord>()
-  /** Most recently resolved binding id — the watch approximation for deferred teardown. */
+  /** Registered per-session standard-props providers, in registration order. */
+  private readonly providers: SessionProvideDescriptor[] = []
+  /** Static no-session projection, rebuilt only when the provider roster changes. */
+  private maybeInfo: SessionMaybeProvideInfo
+  /** Latest published {@link SessionsService.currentProvideInfo} bundle (identity comparison dedupes republish). */
+  private currentProvideInfoSnapshot: SessionMaybeProvideInfo
+  /** currentProvideInfo subscribers (plain cell: bundles hold live Session sources, so no store freeze may touch them). */
+  private readonly currentProvideInfoListeners = new Set<() => void>()
+  /**
+   * The staged session id — follows `list.current` exactly, holding its last
+   * defined value across masked gaps (a transiently absent selection blanks
+   * `current` without moving the stage, so reconnect re-pulls and removals
+   * keep the staged scope's frozen view alive until the stage moves on).
+   */
   private watched: SessionId | undefined
-  /** Removed-while-watched sessions whose teardown waits for the watch to move away. */
+  /** Removed-while-staged sessions whose teardown waits for the stage to move away. */
   private readonly deferredRemovals = new Set<SessionId>()
 
   /**
@@ -89,28 +193,227 @@ export class SessionsService {
    * @param api - wire client shared with every Session.
    */
   constructor(private readonly rootCtx: Context, api: IApiClient) {
-    this.manager = new SessionManager(api)
-    this.list = createSnapshotStore<SessionListState>({ ids: [], byId: {} })
+    this.selection = createSnapshotStore<{ sessionId?: SessionId }>(
+      {},
+      { persist: { name: 'dsh.sessions.current' } })
+    this.manager = new SessionManager(api, this.selection.getSnapshot().sessionId)
+    this.list = createSnapshotStore<SessionListState>({
+      ids: [], byId: {}, current: undefined, phase: 'pending',
+    })
     // The manager owns wire truth; the store is its projection. Manager
     // notifications are already microtask-batched.
     this.manager.subscribe(() => { this.projectList() })
+    // Stage follower: every current write (open() and projection alike)
+    // re-evaluates staging, so startup restore (persisted selection validated
+    // by the projection) and reconnect resurfacing open their window with no
+    // dedicated code path. Safe to run synchronously inside the store notify:
+    // the follower writes no list state — session.open()'s synchronous prefix
+    // touches only session-side state and its own microtask-batched notifier.
+    // The current-provide projection follows the same current writes.
+    this.list.subscribe(() => {
+      this.followCurrent()
+      this.updateCurrentProvideInfo()
+    })
+    // The runtime's own contribution comes first: useSession rides the same
+    // provide channel every plugin uses (no renderer special case).
+    this.providers.push({
+      hooks: ['session'],
+      resolve: binding => ({ hooks: { session: binding.session } }),
+    })
+    this.maybeInfo = this.materializeMaybeProvideInfo()
+    this.currentProvideInfoSnapshot = this.maybeInfo
+    this.currentProvideInfo = {
+      getSnapshot: () => this.currentProvideInfoSnapshot,
+      subscribe: (fn) => {
+        this.currentProvideInfoListeners.add(fn)
+        return () => { this.currentProvideInfoListeners.delete(fn) }
+      },
+    }
     rootCtx.reflect.provide('sessions', this, undefined)
   }
 
   /**
-   * Create a session on the host.
-   * @param opts - creation options (project directory).
-   * @returns the new session id.
+   * Register a per-session standard-props provider: every session-scope slot
+   * component receives the contributed members as standard props (`hooks`
+   * sources become `use<Name>` selector hooks on the render side; `props`
+   * spread verbatim). Contributions materialize lazily with the session's
+   * scope record and die with it. Registration order is resolution order;
+   * duplicate member names fail loud at materialization.
+   * @param descriptor - static member roster plus per-session resolver.
+   * @returns disposer removing the provider (already-materialized bundles keep their members until their scope drops).
    */
-  async create(opts: { cwd?: string } = {}): Promise<SessionId> {
-    const result = await this.manager.create(opts.cwd)
-    if (!result.ok) throw new Error(`session create failed: ${result.error.code}: ${result.error.message}`)
+  provide(descriptor: SessionProvideDescriptor): () => void {
+    this.providers.push(descriptor)
+    // Scopes may already exist (boot order: the list lands and resolves
+    // scopes before later plugins register) — their bundles must include
+    // every provider by first render, so re-materialize on roster change.
+    this.rematerializeProvideBundles()
+    return () => {
+      const at = this.providers.indexOf(descriptor)
+      if (at >= 0) this.providers.splice(at, 1)
+      this.rematerializeProvideBundles()
+    }
+  }
+
+  /** Rebuild every live scope's standard-props bundle after a provider roster change. */
+  private rematerializeProvideBundles(): void {
+    this.maybeInfo = this.materializeMaybeProvideInfo()
+    for (const record of this.scopes.values()) {
+      record.provideInfo = this.materializeProvideInfo(record.binding)
+    }
+    this.updateCurrentProvideInfo()
+  }
+
+  /**
+   * Re-derive the current selection's provide bundle and publish it when it
+   * changed. Bundles are identity-stable per (scope, roster)
+   * materialization, so an identity compare is exact; synchronous notify —
+   * both call sites (list.subscribe, provide()) already sit behind their own
+   * batching or registration edges.
+   */
+  private updateCurrentProvideInfo(): void {
+    const next = this.maybeProvideInfo(this.list.getSnapshot().current)
+    if (next === this.currentProvideInfoSnapshot) return
+    this.currentProvideInfoSnapshot = next
+    for (const fn of [...this.currentProvideInfoListeners]) {
+      try {
+        fn()
+      } catch (error) {
+        // Contain subscriber failures: this notify runs inside the list
+        // notification, where a throwing render-side subscriber would starve
+        // later listeners and abort the projection pass that scheduled it.
+        console.error('sessions.currentProvideInfo subscriber failed:', error)
+      }
+    }
+  }
+
+  /** Build the static no-session kit and reject duplicate declared names. */
+  private materializeMaybeProvideInfo(): SessionMaybeProvideInfo {
+    const hooks: Record<string, undefined> = {}
+    const props: Record<string, undefined> = {}
+    for (const descriptor of this.providers) {
+      for (const name of descriptor.hooks ?? []) {
+        if (Object.hasOwn(hooks, name)) throw new Error(`sessions.provide: duplicate hook "${name}"`)
+        hooks[name] = undefined
+      }
+      for (const name of descriptor.props ?? []) {
+        if (Object.hasOwn(props, name)) throw new Error(`sessions.provide: duplicate prop "${name}"`)
+        props[name] = undefined
+      }
+    }
+    return { sessionId: undefined, hooks, props } // no projections face: every key reads absent without a session
+  }
+
+  /** Materialize the standard-props bundle for one session (fails loud on duplicate member names). */
+  private materializeProvideInfo(binding: SessionBinding): SessionProvideInfo {
+    const hooks: Record<string, HostObservable<unknown>> = {}
+    const props: Record<string, unknown> = {}
+    for (const descriptor of this.providers) {
+      const contribution = descriptor.resolve(binding)
+      const contributedHooks = contribution.hooks ?? {}
+      const contributedProps = contribution.props ?? {}
+      for (const name of Object.keys(contributedHooks)) {
+        if (!(descriptor.hooks ?? []).includes(name)) {
+          throw new Error(`sessions.provide: undeclared hook "${name}"`)
+        }
+      }
+      for (const name of Object.keys(contributedProps)) {
+        if (!(descriptor.props ?? []).includes(name)) {
+          throw new Error(`sessions.provide: undeclared prop "${name}"`)
+        }
+      }
+      for (const name of descriptor.hooks ?? []) {
+        const source = contributedHooks[name]
+        if (source === undefined) throw new Error(`sessions.provide: missing hook "${name}"`)
+        if (Object.hasOwn(hooks, name)) throw new Error(`sessions.provide: duplicate hook "${name}"`)
+        hooks[name] = source
+      }
+      for (const name of descriptor.props ?? []) {
+        if (!Object.hasOwn(contributedProps, name)) throw new Error(`sessions.provide: missing prop "${name}"`)
+        if (Object.hasOwn(props, name)) throw new Error(`sessions.provide: duplicate prop "${name}"`)
+        props[name] = contributedProps[name]
+      }
+    }
+    return {
+      sessionId: binding.sessionId,
+      hooks,
+      props,
+      // The useProjection seat: key-addressed bare value faces off the
+      // session's projection store (open key space — never a static roster member).
+      projections: { faceOf: key => binding.session.projections.faceOf(key) },
+    }
+  }
+
+  /**
+   * Select a session as current. Unknown ids fail loud instead of navigating
+   * nowhere.
+   * @param id - session id (must exist in the list store).
+   */
+  open(id: SessionId): void {
+    this.manager.select(id)
+  }
+
+  /**
+   * Clear the current selection so the layout shows the no-session empty
+   * state (new-session affordance and the workspace preselection flow).
+   * Wipes the persisted selection too — a reload stays on empty until the
+   * user opens or starts a session. The staged scope keeps its frozen view
+   * per the masked-gap contract until the next open() moves the stage.
+   */
+  clear(): void {
+    this.manager.clearSelection()
+  }
+
+  /**
+   * Refresh the real Session baseline, reusing an in-flight pull.
+   * @returns completion of the current or newly started baseline pull.
+   */
+  refresh(): Promise<void> {
+    return this.manager.refreshList()
+  }
+
+  /**
+   * Route a mux stream envelope into the Session object layer.
+   * @param envelope - validated mux stream envelope.
+   */
+  handleMuxEnvelope(envelope: Parameters<SessionManager['handleMuxEnvelope']>[0]): void {
+    this.manager.handleMuxEnvelope(envelope)
+  }
+
+  /**
+   * Route a Host stream envelope into the Session object layer.
+   * @param envelope - validated Host stream envelope.
+   */
+  handleHostEnvelope(envelope: Parameters<SessionManager['handleHostEnvelope']>[0]): void {
+    this.manager.handleHostEnvelope(envelope)
+  }
+
+  /** Rebuild the Session baseline and every opened window after connection. */
+  handleConnected(): void {
+    this.manager.handleConnected()
+  }
+
+  /**
+   * Create a session on the host. Resolution guarantee: by the time the
+   * promise resolves, the created session is in the list store and
+   * {@link SessionsService.binding} resolves it — callers (New Session
+   * draft hand-off) may address the scope synchronously, without waiting a
+   * notifier flush. The synchronous projection below makes this structural
+   * rather than an accident of microtask ordering.
+   * @param opts - target workspace or directory and an optional preallocated id.
+   * @returns the new session id.
+   * @throws {SessionCreateError} with the requested id.
+   */
+  async create(opts: { workspaceId?: WorkspaceId; cwd?: string; sessionId?: SessionId } = {}): Promise<SessionId> {
+    const result = await this.manager.create(opts)
+    if (!result.ok) throw new SessionCreateError(result.error, opts.sessionId)
+    this.projectList()
     return result.value.sessionId
   }
 
   /**
-   * Resolve a session-scoped context view (use-and-discard).
-   * @param id - session id.
+   * Resolve an Agent-scoped context view (use-and-discard).
+   * @param id - session id (the agent identity — 1:1 same axis).
    * @returns scoped ctx, or undefined for a session neither listed nor already scoped.
    */
   scope(id: SessionId): Context | undefined {
@@ -118,18 +421,84 @@ export class SessionsService {
   }
 
   /**
-   * Resolve the stable session binding (SessionProvider's resolveBinding feed).
+   * Read the Agent scope tag off a context. Service-method seam: fetch
+   * bundles must reach scope resolution through ctx.sessions — a cross-bundle
+   * value import of the standalone helper would inline a second module
+   * instance whose private tag Symbol never matches.
+   * @param ctx - any client context.
+   * @returns the session id, or undefined on root contexts.
+   */
+  scopeOf(ctx: Context): SessionId | undefined {
+    return scopeTagOf(ctx)
+  }
+
+  /**
+   * Resolve the business Session behind an Agent-scoped context — the one
+   * hop every scoped consumer (event listeners, per-session controllers)
+   * takes from ctx-space into object-space (the client mirror of host
+   * `agent.session`). Same service-method seam as
+   * {@link SessionsService.scopeOf}.
+   * @param ctx - an Agent-scoped context.
+   * @returns the Session, or undefined when the ctx is untagged or its scope was pruned.
+   */
+  sessionOf(ctx: Context): Session | undefined {
+    const id = scopeTagOf(ctx)
+    if (id === undefined) return undefined
+    return this.scopes.get(id)?.binding.session
+  }
+
+  /**
+   * Resolve the stable session binding (scope-addressed assembly feed). Pure
+   * resolution — no staging, no window side effects.
    * @param id - session id.
    * @returns binding, or undefined for a session neither listed nor already scoped.
    */
   binding(id: SessionId): SessionBinding | undefined {
-    const record = this.resolve(id)
-    if (record === undefined) return undefined
-    if (this.watched !== id) {
-      this.watched = id
-      this.sweepDeferred()
+    return this.resolve(id)?.binding
+  }
+
+  /**
+   * Resolve one session's render-layer standard-props bundle (ctx never
+   * enters the render layer; the renderer subscribes to
+   * {@link SessionsService.currentProvideInfo}). Pure resolution — render-safe:
+   * no staging, no window side effects (StrictMode double-invokes and
+   * concurrent discarded passes must stay free).
+   */
+  private provideInfo(id: string): SessionProvideInfo | undefined {
+    return this.resolve(id as SessionId)?.provideInfo
+  }
+
+  /**
+   * Resolve the current-session-optional standard kit. Unknown or absent ids
+   * return the static no-session projection rather than removing hook props.
+   */
+  private maybeProvideInfo(id: string | undefined): SessionMaybeProvideInfo {
+    return (id === undefined ? undefined : this.provideInfo(id)) ?? this.maybeInfo
+  }
+
+  /**
+   * Move the stage to the list's current session: sweep teardowns deferred
+   * behind the previous occupant and pull the new occupant's history window.
+   * Staging IS the open signal — the window opens ⟺ the session is on stage
+   * — and open() is idempotent (an in-flight or completed open no-ops; a
+   * failed one retries the next time current is touched).
+   */
+  private followCurrent(): void {
+    const snapshot = this.list.getSnapshot()
+    const current = snapshot.current
+    // A masked gap (current blanked while the selection's session is
+    // transiently absent) holds the stage: tearing down on the gap would
+    // destroy exactly the frozen scope the mask exists to preserve.
+    if (current === undefined || snapshot.byId[current] === undefined || current === this.watched) return
+    this.watched = current
+    this.sweepDeferred()
+    const record = this.resolve(current)
+    /* v8 ignore next 3 -- defensive: current is always a listed id (open()
+     * validates and the projection masks absent selections), so resolve
+     * cannot miss; kept so a future current writer cannot crash the notify. */
+    if (record !== undefined) {
+      void record.binding.session.open()
     }
-    return record.binding
   }
 
   /**
@@ -150,66 +519,111 @@ export class SessionsService {
     return chain
   }
 
-  /** Lazily mint the scope + binding for a listed (or already-scoped) session. */
+  /**
+   * Lazily mint the scope + binding for an eligible session. Eligibility and
+   * prune share one predicate (decision 12): listed on the host — a scope is
+   * born when its session enters the client's view (list mirror row from the
+   * baseline pull, a create() echo, or the session-added frame) and dies with
+   * the prune when the row leaves.
+   */
   private resolve(id: SessionId): ScopeRecord | undefined {
     const existing = this.scopes.get(id)
     if (existing !== undefined) return existing
-    // Frozen scopes outlive the list; new scopes are only minted for listed sessions.
-    if (this.list.getSnapshot().byId[id] === undefined) return undefined
-    const fiber = this.rootCtx.plugin(sessionScope)
-    const ctx = fiber.ctx.extend({ [kScope]: id })
+    if (!this.eligible(id)) return undefined
+    const { fiber, ctx } = createScope(this.rootCtx, id)
+    const session = this.manager.get(id)
+    // The Session owns its scoped dispatch point (host Agent.loopCtx mirror);
+    // mint and bind are one step so a live scope record implies a bound actx.
+    session.bindScope(ctx)
+    const binding: SessionBinding = { sessionId: id, session, ctx }
     const record: ScopeRecord = {
       fiber,
       ctx,
-      binding: { sessionId: id, session: this.manager.get(id), ctx },
+      binding,
+      // Sources are bare observables; React binds selector hooks at its own seam.
+      provideInfo: this.materializeProvideInfo(binding),
     }
     this.scopes.set(id, record)
     return record
   }
 
+  /** The one aliveness predicate shared by scope mint and prune: host-listed. */
+  private eligible(id: SessionId): boolean {
+    return this.list.getSnapshot().byId[id] !== undefined
+  }
+
   /** Project the manager's list snapshot into the store (title derivation is display-only). */
   private projectList(): void {
-    const items = this.manager.getListSnapshot().items
+    const { items, current, phase } = this.manager.getListSnapshot()
     const ids: SessionId[] = []
     const byId: Record<SessionId, SessionSummary> = {}
     for (const entry of items) {
       ids.push(entry.sessionId)
       byId[entry.sessionId] = {
         id: entry.sessionId,
-        title: titleOf(entry.cwd, entry.sessionId),
+        displayTitle: displayTitleOf(entry.title, entry.cwd, entry.sessionId),
         running: entry.running,
+        blank: entry.blank,
         updatedAt: entry.updatedAt,
+        ...(entry.title !== undefined ? { title: entry.title } : {}),
         ...(entry.cwd !== undefined ? { cwd: entry.cwd } : {}),
         ...(entry.parentSessionId !== undefined ? { parentId: entry.parentSessionId } : {}),
       }
     }
-    this.list.set({ ids, byId })
+    const persisted = this.selection.getSnapshot().sessionId
+    // No current (cleared, or masked gap) wipes the persisted cell — a reload
+    // stays on empty; the in-memory selection still resurfaces a masked id.
+    if (current === undefined) {
+      if (persisted !== undefined) this.selection.set({})
+    } else if (byId[current] !== undefined && persisted !== current) {
+      this.selection.set({ sessionId: current })
+    }
+    this.list.set({ ids, byId, current, phase })
     this.pruneScopes(byId)
   }
 
-  /** Tear down scopes for removed sessions nobody watches; the watched one defers until the watch moves. */
+  /** Tear down scope + instance for no-longer-eligible sessions off stage; the staged one defers until the stage moves. */
   private pruneScopes(byId: Record<SessionId, SessionSummary>): void {
+    void byId
     for (const [id, record] of this.scopes) {
-      if (byId[id] !== undefined) continue
+      if (this.eligible(id)) continue
       if (id === this.watched) {
         this.deferredRemovals.add(id)
         continue
       }
       this.scopes.delete(id)
       this.deferredRemovals.delete(id)
-      void record.fiber.dispose()
+      this.dropScope(id, record)
     }
   }
 
-  /** Run deferred teardowns whose session is no longer watched (called when the watch moves). */
+  /**
+   * One teardown for the whole per-session axis (decision 12): the scope
+   * fiber (cascading every actx-registered effect: input shell, slash
+   * controller, popup, plugin stores, listeners), the session-keyed slot
+   * stores, and the Session instance itself — the host session log is the
+   * durable truth, a reopen lazily rebuilds and backfills via open().
+   */
+  private dropScope(id: SessionId, record: ScopeRecord): void {
+    void record.fiber.dispose()
+    // Release the Session's dispatch point with the scope it belongs to (a
+    // surviving instance — the live Intent — rebinds when resolve re-mints).
+    record.binding.session.unbindScope()
+    // Optional lookup: slots and sessions are sibling services with no
+    // declared dependency; a slots-less boot (object-layer tests) skips.
+    this.rootCtx.get('slots')?.pruneStoreScope(id)
+    this.manager.drop(id)
+  }
+
+  /** Run deferred teardowns whose session is no longer staged (called when the stage moves). */
   private sweepDeferred(): void {
     for (const id of [...this.deferredRemovals]) {
-      /* v8 ignore next -- defensive: only the watched id ever defers, and every
-       * watch move sweeps first, so the set cannot contain the id the watch just
+      /* v8 ignore next -- defensive: only the staged id ever defers, and every
+       * stage move sweeps first, so the set cannot contain the id the stage just
        * moved to; kept as a guard against future extra sweep call sites. */
       if (id === this.watched) continue
-      // Still absent from the list? (A re-added id cancels the deferred teardown.)
-      if (this.list.getSnapshot().byId[id] !== undefined) {
+      // Eligible again? (A re-added id cancels the deferred teardown.)
+      if (this.eligible(id)) {
         this.deferredRemovals.delete(id)
         continue
       }
@@ -220,7 +634,7 @@ export class SessionsService {
        * future teardown path cannot double-dispose. */
       if (record !== undefined) {
         this.scopes.delete(id)
-        void record.fiber.dispose()
+        this.dropScope(id, record)
       }
     }
   }

packages/client/runtime/src/client/sessions/session.ts

@@ -1,29 +1,75 @@
-// Session: wraps every contract call that needs a sessionId + all conversation state for this
-// session (design §A.2/§A.9/§D.2/§D.3). Instances are resident (ruling 2): never destroyed once
-// created, they keep consuming mux frames in the background; React connects directly via
-// subscribe/getSnapshot.
+// Sessions remain resident after creation so they continue consuming mux frames off-screen.
 
+import type { Context } from 'cordis'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
-import type { GoalView, HistoryEntry, IApiClient, MuxFrame, RpcError, RpcId, RpcResult, SessionId, ToolEventView } from '@deepseek-ai/dsh-client-connection/client'
-import { transportError } from '@deepseek-ai/dsh-client-connection/client'
-import type { ObservableSnapshot, SnapshotSelectorHook } from '@deepseek-ai/dsh-client-web-react'
-import { bindSnapshotSelector } from '@deepseek-ai/dsh-client-web-react'
 import type {
-  ConversationNode, ConversationSnapshot, OpenState, PendingInteraction, PromptError, RunningToolCall,
+  HistoryEntry, IApiClient, MuxFrame, RpcError, RpcId, RpcResult,
+  SessionId, ToolEventView,
+} from '@deepseek-ai/dsh-client-connection/client'
+// Value import from the inline-safe wire layer (not the connection plugin):
+// plugin-to-plugin value imports are a bundle purity error.
+import { transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
+import type { ObservableSnapshot } from '../contract/store.ts'
+import type {
+  CodeSubCall, ComposerPhase, ConversationNode, ConversationSnapshot, OpenState,
+  PromptError, QueuedMessage, RunningToolCall,
 } from './conversation.ts'
+import type { PendingInteraction } from './pending.ts'
+import { PendingWait } from './pending.ts'
 import { FoldAdapter } from './fold-adapter.ts'
 import { Notifier } from './notifier.ts'
 import { PartialAccumulator } from './partial.ts'
+import { ProjectionValueStore } from './projection-store.ts'
+import type { ProjectionsBaseline } from './projection-store.ts'
 
-/** Messages per page (F.4 ledger: promote to Config at graduation; every call site references this constant). */
+/** Messages requested per history page. */
 export const PAGE_MESSAGES = 50
 
-/** Per-session state owner: event window + fold + partial, snapshot out via uSES (see the web client architecture RFC). */
-export class Session implements ObservableSnapshot<ConversationSnapshot> {
-  /** Typed selector hook bound to this instance (the SessionBinding `useSession` source). */
-  readonly useSelector: SnapshotSelectorHook<ConversationSnapshot> = bindSnapshotSelector(this)
+/** Manager-owned observers of a Session object's local state edges. */
+export interface SessionOptions {
+  /**
+   * First ACCEPTED prompt on a blank session (fires at most once, on the
+   * prompt RPC's success response): the manager mirrors the blank→false flip
+   * into its list row so the session surfaces without waiting for a host
+   * frame. Acceptance is the flip point because it proves the user message
+   * is in the host log; a rejected first prompt keeps the session blank
+   * (hidden, still reusable by connectWorkspace).
+   */
+  onEngaged?(session: Session): void
+  /**
+   * Manager-owned projection value store to adopt (frames route through the
+   * manager and values outlive instantiation); omitted, the Session owns a
+   * private store (bare object-layer construction).
+   */
+  projections?: ProjectionValueStore
+}
 
+/** Queue-row preview cap: the dock renders one line, the full content never leaves the host mirror. */
+const QUEUE_PREVIEW_CHARS = 200
+
+/** Internal inbox-mirror entry: the snapshot row plus the retirement-matching fields the frames carry. */
+interface QueuedEntry {
+  row: QueuedMessage
+  steering: boolean
+  /** JSON-serialized MessageSource (steering retirement matches by source, the host-mirror precedent). */
+  sourceJson: string
+}
+
+/** Single-line queue-row preview: text blocks flattened, non-text as tags, capped by code point. */
+function queuePreviewOf(content: readonly ContentBlock[]): string {
+  const flat = content
+    .map(block => (block.type === 'text' ? block.text : `[${block.type}]`))
+    .join(' ').replace(/\s+/g, ' ').trim()
+  const chars = Array.from(flat)
+  return chars.length > QUEUE_PREVIEW_CHARS ? `${chars.slice(0, QUEUE_PREVIEW_CHARS).join('')}…` : flat
+}
+
+/**
+ * Owns a session's event window, derived conversation state, and observable
+ * snapshot. React bindings remain outside this data layer.
+ */
+export class Session implements ObservableSnapshot<ConversationSnapshot> {
   // ---- Window and derived state (all private; the snapshot is the only read surface) ----
   private events: SessionEvent[] = []
   /** Wire views aligned with `events` by index (envelope-level annotations; undefined = no view).
@@ -46,8 +92,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
    *  Derived from window events (turn/end sweep) — rebuilt by rebuildDerivedFromWindow like partial/openCalls. */
   private frozenNodes: ConversationNode[] = []
   private pending = new Map<string, PendingInteraction>()
-  // Revision counters + caches backing the snapshot's reference-stability contract (§A.9.4/§C.2,
-  // audit S5): buildSnapshot reuses the previous array when the revision is unchanged, so
+  // Revision counters preserve array identity when derived content is unchanged, so
   // React.memo children survive unrelated snapshot swaps (chunk storms must not re-render every
   // tool card and pending card). Mutation sites bump the matching revision. partial needs no
   // counter — PartialAccumulator.toPartial already returns a cached reference when unchanged.
@@ -55,36 +100,95 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
   private callsCache: { rev: number; value: RunningToolCall[] } | null = null
   private pendingRev = 0
   private pendingCache: { rev: number; value: PendingInteraction[] } | null = null
+  /** Inbox mirror (session/queued frames + mux-open baseline). Queue frames never hit history,
+   *  so this is stream-only state: reconnect clears it and the fresh baseline re-populates. */
+  private queued: QueuedEntry[] = []
+  private queueRev = 0
+  private queueCache: { rev: number; value: QueuedMessage[] } | null = null
   private frozenRev = 0
   private nodesCache: { folded: readonly ConversationNode[]; frozenRev: number; value: readonly ConversationNode[] } | null = null
+  /** `run_code` sub-dispatches by parent callId (window-derived, like openCalls). Appends
+   *  copy-on-write the per-parent array so published snapshot references never mutate. */
+  private codeDispatches = new Map<string, readonly CodeSubCall[]>()
+  private dispatchesRev = 0
+  private dispatchesCache: { rev: number; value: ReadonlyMap<string, readonly CodeSubCall[]> } | null = null
   private running = false
+  /**
+   * Sticky send marker, private input of the composerPhase derivation: set
+   * synchronously before prompt()'s first await, never reset — the blank →
+   * engaging edge of the phase machine (see ComposerPhase).
+   */
+  private promptAttempted = false
+  /** Empty-log mirror (see ConversationSnapshot.blank); monotone false once flipped. */
+  private blankBit = false
   private removed = false
   private promptError: PromptError | null = null
   private lastAgentError: string | null = null
-  /** Current goal projection; undefined = not yet fetched, null = no goal set. */
-  private goal: GoalView | null | undefined = undefined
-  /** Coalesced goal refetch; a trigger received in flight schedules one trailing read. */
-  private goalFetch: Promise<void> | null = null
-  private goalFetchPending = false
-  /** Bumped on every local goal write; a get result older than the latest write is stale and
-   *  dropped (a mutation response that landed mid-fetch is always newer than the get's read). */
-  private goalWriteRev = 0
-  /** Buffer for live events arriving while open/resync is in flight (stitched by seq once history lands, §D.3). */
+  /** Live events buffered during open/resync and stitched by sequence once history lands. */
   private liveBuffer: { event: SessionEvent; view: ToolEventView | undefined }[] = []
-  /** Gap-repair (resync-lite) in flight: acceptLiveEvent detours to liveBuffer until the tail page lands (audit S3). */
+  /** Gap repair in flight; live events detour to the buffer until the tail page lands. */
   private stitching = false
   /** subscribed.lastSeq baseline (gap detection; null when no subscribed frame arrived — degrade to the liveBuffer dedup path). */
   private subscribedLastSeq: number | null = null
 
+  /**
+   * Per-session projection value store (session-projection RFC, push model):
+   * finished whole values computed on the host, seeded by the tail page's
+   * projections block and updated by `session/projection` frames under the
+   * one higher-seq-wins rule. Keys are read via `projections.faceOf(key)`
+   * (the useProjection resolution face); the conversation snapshot never
+   * carries projection values, and no client-side domain folding exists.
+   * Manager-owned when constructed through SessionManager (frames route and
+   * the store outlives instantiation, the title-snapshot precedent); a bare
+   * construction gets a private store.
+   */
+  readonly projections: ProjectionValueStore
+
   private snapshotCache: ConversationSnapshot
   private readonly notifier = new Notifier(() => {
     this.snapshotCache = this.buildSnapshot()
   })
+  /**
+   * Agent-scoped cordis context, bound once by SessionsService when it
+   * mints the scope (the client mirror of the host Agent's loopCtx). The
+   * Session dispatches its own scoped events through it; undefined means
+   * unbound (bare object-layer construction) or already pruned — both skip
+   * dispatch-dependent behavior rather than fail.
+   */
+  private actx: Context | undefined
 
-  constructor(readonly sessionId: SessionId, private readonly api: IApiClient) {
+  /**
+   * @param sessionId - Host session identity (client sessions are always Host-born).
+   * @param api - shared wire client.
+   * @param options - optional manager-owned state observers.
+   */
+  constructor(
+    readonly sessionId: SessionId,
+    private readonly api: IApiClient,
+    private readonly options: SessionOptions = {},
+  ) {
+    this.projections = options.projections ?? new ProjectionValueStore()
     this.snapshotCache = this.buildSnapshot()
   }
 
+  /**
+   * Bind the Agent-scoped context minted by SessionsService (single write;
+   * a second bind is a wiring error and throws). Direction stays one-way at
+   * the seam: consumers still reach the Session via `sessions.sessionOf`,
+   * while the Session holds its own dispatch point (host Agent.loopCtx
+   * mirror).
+   * @param actx - the agent's scoped context.
+   */
+  bindScope(actx: Context): void {
+    if (this.actx !== undefined) throw new Error(`session ${this.sessionId} already has a bound scope`)
+    this.actx = actx
+  }
+
+  /** Release the bound scope at prune time (a later rebind accompanies a freshly minted scope). */
+  unbindScope(): void {
+    this.actx = undefined
+  }
+
   // ---- Operations ----
 
   /**
@@ -96,6 +200,10 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
   async prompt(content: ContentBlock[], mode: 'queue' | 'steer'): Promise<RpcResult<{ accepted: true }>> {
     this.promptError = null
     this.lastAgentError = null
+    // Synchronous, before the first await: the blank → engaging edge must be
+    // visible on the session area's very first frame when a caller sends
+    // ahead of navigation (first-send flow).
+    this.promptAttempted = true
     this.notifier.markDirty()
     let result: RpcResult<{ accepted: true }>
     try {
@@ -106,6 +214,18 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     if (!result.ok) {
       this.promptError = { op: 'send', error: result.error }
       this.notifier.markDirty()
+      return result
+    }
+    // Blank flips on ACCEPTANCE, not attempt: an accepted prompt has logged
+    // its user/message on the host (events.length > 0 is fact, not
+    // optimism), while a rejected first prompt must keep the session blank
+    // — the client-side blank mirror only ever lowers, so flipping early on
+    // a failure would surface the session forever and strip its
+    // connectWorkspace reuse eligibility against the host's authority.
+    if (this.blankBit) {
+      this.blankBit = false
+      this.options.onEngaged?.(this)
+      this.notifier.markDirty()
     }
     return result
   }
@@ -128,148 +248,6 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     return result
   }
 
-  /** Fetch the current goal, coalesced: concurrent triggers share the in-flight get. */
-  private fetchGoal(): Promise<void> {
-    if (this.goalFetch !== null) {
-      this.goalFetchPending = true
-      return this.goalFetch
-    }
-    const promise = this.drainGoalFetches().finally(() => { this.goalFetch = null })
-    this.goalFetch = promise
-    return promise
-  }
-
-  /** Drain the current read plus one coalesced trailing read for triggers received in flight. */
-  private async drainGoalFetches(): Promise<void> {
-    do {
-      this.goalFetchPending = false
-      await this.doFetchGoal()
-      // A goal-change callback can set the flag while doFetchGoal is suspended.
-      // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
-    } while (this.goalFetchPending)
-  }
-
-  /** The get behind fetchGoal: folds transport failures (fail-soft like loadOlder, logged) and
-   *  drops the result when a mutation response landed mid-flight (write revision moved on). */
-  private async doFetchGoal(): Promise<void> {
-    const writeRev = this.goalWriteRev
-    try {
-      const { result } = await this.api.goals.get({ sessionId: this.sessionId })
-      if (!result.ok) return
-      if (writeRev !== this.goalWriteRev) return
-      this.goal = result.value.goal
-      this.notifier.markDirty()
-    } catch (error) {
-      console.error('[web-runtime] goal fetch failed:', error)
-    }
-  }
-
-  /** Execute a goal mutation and publish its successful projection. */
-  private async updateGoal(
-    request: () => Promise<{ result: RpcResult<{ goal: GoalView }> }>,
-  ): Promise<RpcResult<{ goal: GoalView }>> {
-    let result: RpcResult<{ goal: GoalView }>
-    try {
-      result = (await request()).result
-    } catch (error) {
-      result = transportError(error)
-    }
-    if (result.ok) {
-      this.goal = result.value.goal
-      this.goalWriteRev++
-      this.notifier.markDirty()
-    }
-    return result
-  }
-
-  /**
-   * Create a goal for this session.
-   * @param objective - the goal's objective text.
-   * @param maxGoalRounds - optional cap on admitted goal rounds (host default when absent).
-   * @returns the created goal view; transport failures fold into a failed result, never a rejection.
-   */
-  async createGoal(objective: string, maxGoalRounds?: number): Promise<RpcResult<{ goal: GoalView }>> {
-    return this.updateGoal(() => this.api.goals.create({
-      sessionId: this.sessionId, objective, ...(maxGoalRounds !== undefined ? { maxGoalRounds } : {}),
-    }))
-  }
-
-  /**
-   * Edit this session's goal objective or round cap (CAS with the locally held revision).
-   * @param objective - replacement objective text; absent leaves it unchanged.
-   * @param maxGoalRounds - replacement round cap; absent leaves it unchanged.
-   * @returns the updated goal view; fails without a current goal, and transport failures fold into a failed result.
-   */
-  async editGoal(objective?: string, maxGoalRounds?: number): Promise<RpcResult<{ goal: GoalView }>> {
-    if (this.goal === null || this.goal === undefined) {
-      return { ok: false, error: { code: 'internal', message: 'No goal to edit', details: {} } }
-    }
-    const goal = this.goal
-    return this.updateGoal(() => this.api.goals.edit({
-      sessionId: this.sessionId,
-      ref: { id: goal.id, revision: goal.revision },
-      ...(objective !== undefined ? { objective } : {}),
-      ...(maxGoalRounds !== undefined ? { maxGoalRounds } : {}),
-    }))
-  }
-
-  /** Apply a phase transition to the current goal. */
-  private transitionGoal(operation: 'pause' | 'resume' | 'complete'): Promise<RpcResult<{ goal: GoalView }>> {
-    if (this.goal === null || this.goal === undefined) {
-      return Promise.resolve({ ok: false, error: { code: 'internal', message: `No goal to ${operation}`, details: {} } })
-    }
-    const ref = { id: this.goal.id, revision: this.goal.revision }
-    return this.updateGoal(() => this.api.goals[operation]({ sessionId: this.sessionId, ref }))
-  }
-
-  /**
-   * Pause the current goal (CAS with the locally held revision).
-   * @returns the updated goal view; fails without a current goal, and transport failures fold into a failed result.
-   */
-  async pauseGoal(): Promise<RpcResult<{ goal: GoalView }>> {
-    return this.transitionGoal('pause')
-  }
-
-  /**
-   * Resume a paused/blocked goal (CAS with the locally held revision).
-   * @returns the updated goal view; fails without a current goal, and transport failures fold into a failed result.
-   */
-  async resumeGoal(): Promise<RpcResult<{ goal: GoalView }>> {
-    return this.transitionGoal('resume')
-  }
-
-  /**
-   * Complete the current goal (CAS with the locally held revision).
-   * @returns the updated goal view; fails without a current goal, and transport failures fold into a failed result.
-   */
-  async completeGoal(): Promise<RpcResult<{ goal: GoalView }>> {
-    return this.transitionGoal('complete')
-  }
-
-  /**
-   * Clear the current goal (tombstone; CAS with the locally held revision).
-   * @returns a cleared marker; fails without a current goal, and transport failures fold into a failed result.
-   */
-  async clearGoal(): Promise<RpcResult<{ cleared: true }>> {
-    if (this.goal === null || this.goal === undefined) {
-      return { ok: false, error: { code: 'internal', message: 'No goal to clear', details: {} } }
-    }
-    let result: RpcResult<{ cleared: true }>
-    try {
-      result = (await this.api.goals.clear({
-        sessionId: this.sessionId, ref: { id: this.goal.id, revision: this.goal.revision },
-      })).result
-    } catch (error) {
-      result = transportError(error)
-    }
-    if (result.ok) {
-      this.goal = null
-      this.goalWriteRev++
-      this.notifier.markDirty()
-    }
-    return result
-  }
-
   /** First open: pull the tail page (idempotent — in-flight/already-open returns the existing promise). */
   open(): Promise<void> {
     if (this.openState === 'open') return Promise.resolve()
@@ -324,6 +302,11 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
    *  in-flight open first — its history request rode the dead connection and must not settle
    *  the fresh generation into 'error' (audit S4). */
   async resync(): Promise<void> {
+    // The queue mirror is NOT cleared here: onConnected (which drives resync)
+    // races the mux frames — the fresh generation's baseline may have landed
+    // already, and the host never resends it. The mirror re-baselines on the
+    // session/subscribed frame instead (same stream as the queue snapshot
+    // that follows it, so ordering is guaranteed).
     if (this.openState === 'cold') return // never opened: no window to rebuild (doOpen flips to 'loading' synchronously, so cold implies no in-flight open)
     this.openGeneration++
     this.openPromise = null
@@ -332,7 +315,9 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     this.events = []
     this.views = []
     this.baseSeq = 0
-    this.pending.clear() // the subscribed baseline replay re-sends still-pending requested frames verbatim
+    // Superseded, not settled: the baseline replay re-sends still-pending requested frames verbatim
+    // (same rpcId), re-minting fresh waits; a stale reference's respond() still reaches the host.
+    this.pending.clear()
     this.pendingRev++
     this.subscribedLastSeq = null
     this.liveBuffer = []
@@ -370,41 +355,59 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
   handleMuxEnvelope(rpcId: RpcId, frame: MuxFrame): void {
     switch (frame.type) {
       case 'session/event': {
+        this.retireQueued(frame.event)
         this.acceptLiveEvent(frame.event, frame.view)
         return
       }
+      case 'session/queued': {
+        const message = frame.message
+        // Row key: the enqueueing prompt's rpcId when it rode this wire (the
+        // provisional-echo reconciliation key); otherwise the frame envelope id.
+        const key = 'rpcId' in message.source ? String(message.source.rpcId) : `f:${rpcId}`
+        this.queued.push({
+          row: { key, preview: queuePreviewOf(message.content) },
+          steering: frame.steering,
+          sourceJson: JSON.stringify(message.source),
+        })
+        this.queueRev++
+        this.notifier.markDirty()
+        return
+      }
       case 'session/subscribed': {
         this.subscribedLastSeq = frame.lastSeq
-        return // pure baseline bookkeeping, no visible change
+        // New mux-generation baseline: the host pushes this session's queue
+        // snapshot AFTER the subscribed frame on the same stream, so the
+        // stale mirror clears here — race-free against onConnected/resync
+        // timing (clearing there could wipe a baseline that already landed).
+        if (this.queued.length > 0) {
+          this.queued = []
+          this.queueRev++
+          this.notifier.markDirty()
+        }
+        return
       }
       case 'approval/requested': {
-        this.pending.set(`a:${rpcId}`, {
-          kind: 'approval', rpcId, approvalId: frame.approvalId, toolName: frame.toolName,
-          ...(frame.callId !== undefined ? { callId: frame.callId } : {}),
-          ...(frame.reason !== undefined ? { reason: frame.reason } : {}),
-        })
-        this.pendingRev++
+        const { type: _type, sessionId: _sid, ...payload } = frame
+        this.mint(new PendingWait('approval', rpcId, this.sessionId, payload, m => this.api.respond(m)))
         this.notifier.markDirty()
         return
       }
       case 'approval/resolved': {
-        for (const [key, item] of this.pending) {
-          if (item.kind === 'approval' && item.approvalId === frame.approvalId) {
-            this.pending.delete(key)
-            this.pendingRev++
-          }
+        for (const item of this.pending.values()) {
+          if (item.kind === 'approval' && item.payload.approvalId === frame.approvalId) this.settle(item)
         }
         this.notifier.markDirty()
         return
       }
       case 'question/requested': {
-        this.pending.set(`q:${rpcId}`, { kind: 'question', rpcId, questions: frame.questions })
-        this.pendingRev++
+        const { type: _type, sessionId: _sid, ...payload } = frame
+        this.mint(new PendingWait('question', rpcId, this.sessionId, payload, m => this.api.respond(m)))
         this.notifier.markDirty()
         return
       }
       case 'question/resolved': {
-        if (this.pending.delete(`q:${frame.questionRpcId}`)) this.pendingRev++
+        const item = this.pending.get(`q:${frame.questionRpcId}`)
+        if (item !== undefined) this.settle(item)
         this.notifier.markDirty()
         return
       }
@@ -418,11 +421,40 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
    * @param running - the new running state.
    */
   handleRunning(running: boolean): void {
+    // Leave-running sweep (host queuedMirror precedent): discard paths (cancel,
+    // terminal steering drop) have no per-entry frame, so ANY not-running signal
+    // with a nonempty mirror clears it — checked before the equality return so a
+    // stale replay on an already-idle session still sweeps.
+    if (!running && this.queued.length > 0) {
+      this.queued = []
+      this.queueRev++
+      this.notifier.markDirty()
+    }
+    // Turn-start conversion: a blank session never runs, so the first
+    // running:true proves another端's first message landed (设计稿 2.2).
+    if (running && this.blankBit) {
+      this.blankBit = false
+      this.notifier.markDirty()
+    }
     if (this.running === running) return
     this.running = running
     this.notifier.markDirty()
   }
 
+  /**
+   * Blank-bit relay from the authoritative summary source (list baseline and
+   * the session-added frame). Monotone: once any signal (local first send,
+   * running flip, an earlier summary) cleared it, a stale true never
+   * re-blanks.
+   * @param blank - the summary's derived empty-log bit.
+   */
+  handleBlank(blank: boolean): void {
+    if (blank === this.blankBit) return
+    if (blank && (this.promptAttempted || this.running)) return
+    this.blankBit = blank
+    this.notifier.markDirty()
+  }
+
   /** host/session-removed relay: flag the snapshot (instance survives — resident-instance rule). */
   handleRemoved(): void {
     this.removed = true
@@ -438,12 +470,24 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     this.notifier.markDirty()
   }
 
-  /** Instance-eviction hook, reserved no-op (design §F.6): resident instances are never destroyed
-   *  in v1; an eviction policy lands here (unsubscribe, drop buffers) without touching call sites. */
+  /** No-op because session instances remain resident. */
   dispose(): void {}
 
   // ---- 私有 ----
 
+  /** Requested-frame arrival: the wait enters the pending map under its own key. */
+  private mint(wait: PendingInteraction): void {
+    this.pending.set(wait.key, wait)
+    this.pendingRev++
+  }
+
+  /** Authoritative resolved-frame settlement: mark, then drop from the pending map. */
+  private settle(wait: PendingInteraction): void {
+    wait.markSettled()
+    this.pending.delete(wait.key)
+    this.pendingRev++
+  }
+
   /** @param generation - openGeneration at launch; every await re-checks it and a stale pass
    *  drops all writes (resync superseded this open — its outcome belongs to a dead connection). */
   private async doOpen(generation: number): Promise<void> {
@@ -458,17 +502,15 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
         this.openError = result.error
         return
       }
-      this.installWindow(result.value.events, result.value.hasMore)
+      this.installWindow(result.value.events, result.value.hasMore, result.value.projections)
       // Gap detection (§D.3-4): baseline past the window tail and liveBuffer did not cover it -> pull the tail page once more.
       const tailSeq = this.windowTailSeq()
       if (this.subscribedLastSeq !== null && tailSeq !== null && this.subscribedLastSeq > tailSeq) {
         result = (await this.api.sessions.history({ sessionId: this.sessionId, maxMessages: PAGE_MESSAGES })).result
         if (generation !== this.openGeneration) return
-        if (result.ok) this.installWindow(result.value.events, result.value.hasMore)
+        if (result.ok) this.installWindow(result.value.events, result.value.hasMore, result.value.projections)
       }
       this.openState = 'open'
-      // Fetch the current goal eagerly after the window lands.
-      void this.fetchGoal()
     } catch (error) {
       if (generation !== this.openGeneration) return
       this.openState = 'error'
@@ -483,14 +525,18 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
   /** Install the history window + stitch the liveBuffer (seq is the sole dedup key).
    *  Stitching MUST NOT route through acceptLiveEvent: openState is still 'loading' here
    *  (doOpen flips it after install), so recursing would push every buffered event straight
-   *  back into liveBuffer where nothing ever drains it — a silent drop loop (audit S1). */
-  private installWindow(entries: HistoryEntry[], hasMore: boolean): void {
+   *  back into liveBuffer where nothing ever drains it — a silent drop loop (audit S1).
+   *  A carried projections block seeds the value store (higher seq wins, so a stale
+   *  baseline cannot overwrite a newer push frame); the window events themselves are
+   *  never folded — the host is the only computation site. */
+  private installWindow(entries: HistoryEntry[], hasMore: boolean, projections?: ProjectionsBaseline): void {
     this.events = entries.map(e => e.event)
     this.views = entries.map(e => e.view)
     this.baseSeq = this.events[0]?.seq ?? 0
     this.hasMore = hasMore
     this.foldAdapter.reset(this.events, this.baseSeq, this.views)
     this.rebuildDerivedFromWindow()
+    if (projections !== undefined) this.projections.seed(projections)
     const buffered = this.liveBuffer
     this.liveBuffer = []
     for (const item of buffered) this.appendLive(item.event, item.view)
@@ -505,13 +551,6 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     this.views.push(view)
     this.foldAdapter.append(event, view)
     this.applyEventSideEffects(event, view)
-    // Goal mutations surface as goal/change meta on a context/message (clear tombstones carry no
-    // goal key, so match the meta kind). LIVE events only: window rebuilds replay the same meta
-    // and would storm goal.get on open/resync/loadOlder; the refetch coalesces via goalFetch.
-    if (event.type === 'context/message'
-      && (event.data.meta as { kind?: unknown } | undefined)?.kind === 'goal/change') {
-      void this.fetchGoal()
-    }
   }
 
   /** Land a live session/event (open/repair in flight -> buffer; overlapping seq -> drop;
@@ -546,7 +585,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
       const { result } = await this.api.sessions.history({ sessionId: this.sessionId, maxMessages: PAGE_MESSAGES })
       // Failure or superseded by a full resync: drop — the resync path rebuilds and clears the buffer itself.
       if (result.ok && generation === this.openGeneration && this.openState === 'open') {
-        this.installWindow(result.value.events, result.value.hasMore)
+        this.installWindow(result.value.events, result.value.hasMore, result.value.projections)
       }
     } catch (error) {
       console.error('[web-runtime] gap repair failed:', error)
@@ -555,9 +594,89 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     }
   }
 
+  /** Consumption-event retirement, mirroring the host queuedMirror rules: a message-triggered
+   *  turn/start claims the oldest non-steering entry; a steering/message drains the oldest
+   *  steering entry with the same source (loop-authored steering matches nothing and drops none). */
+  private retireQueued(event: SessionEvent): void {
+    if (this.queued.length === 0) return
+    let index = -1
+    if (event.type === 'turn/start') {
+      if (event.data.trigger.kind !== 'message') return
+      index = this.queued.findIndex(entry => !entry.steering)
+    } else if (event.type === 'steering/message') {
+      const source = JSON.stringify(event.data.message.source)
+      index = this.queued.findIndex(entry => entry.steering && entry.sourceJson === source)
+    } else {
+      return
+    }
+    if (index < 0) return
+    this.queued.splice(index, 1)
+    this.queueRev++
+    this.notifier.markDirty()
+  }
+
   /** Per-event side effects (right column of the §A.9 dispatch table):
    *  chunk accumulation / partial clear on finalize / openCalls add-remove. */
   private applyEventSideEffects(event: SessionEvent, view?: ToolEventView): void {
+    // The `tool/code-dispatch-start`/`tool/code-dispatch` pair is declared by
+    // the host-side dsh-tools plugin whose types cannot enter the client
+    // program (its host Context merges collide with the client's), so this
+    // wire consumer narrows them structurally — the same posture as every
+    // other cross-wire event payload.
+    if ((event.type as string) === 'tool/code-dispatch-start') {
+      // A started sub-dispatch enters the index as a RunningToolCall — the
+      // exact shape a native in-flight call renders from — under its parent
+      // run_code callId; it never joins the surface flow.
+      const data = event.data as unknown as {
+        parentCallId: string
+        subCallId: string
+        name: string
+        arguments: unknown
+      }
+      const running: CodeSubCall = {
+        callId: data.subCallId, name: data.name,
+        argsRaw: JSON.stringify(data.arguments),
+        turn: 0, step: 0, time: event.time, callView: null,
+      }
+      const siblings = this.codeDispatches.get(data.parentCallId) ?? []
+      this.codeDispatches.set(data.parentCallId, [...siblings, running])
+      this.dispatchesRev++
+      return
+    }
+    if ((event.type as string) === 'tool/code-dispatch') {
+      // Settlement replaces the running entry in place (same array position,
+      // so parallel sub-calls keep their start order) with the
+      // ToolResultNode form; a settle with no observed start (history window
+      // cut mid-pair, or a pre-start-event log) appends directly.
+      const data = event.data as unknown as {
+        parentCallId: string
+        subCallId: string
+        name: string
+        arguments: unknown
+        isError: boolean
+        content: ContentBlock[]
+      }
+      const siblings = this.codeDispatches.get(data.parentCallId) ?? []
+      const at = siblings.findIndex(sub => sub.callId === data.subCallId)
+      const started = at === -1 ? undefined : siblings[at]
+      const settled: CodeSubCall = {
+        kind: 'tool-result', seq: event.seq, time: event.time,
+        callId: data.subCallId,
+        call: { name: data.name, argsRaw: JSON.stringify(data.arguments) },
+        // Duration source: the paired start's time when observed; null =
+        // unknown (settle-only window), matching the native tool-result
+        // contract so views never present a fabricated zero duration.
+        callTime: started === undefined ? null : started.time,
+        content: data.content, isError: data.isError,
+        callView: null, resultView: null,
+      }
+      this.codeDispatches.set(
+        data.parentCallId,
+        at === -1 ? [...siblings, settled] : siblings.map((sub, index) => (index === at ? settled : sub)),
+      )
+      this.dispatchesRev++
+      return
+    }
     switch (event.type) {
       case 'assistant/chunk': {
         const { turn, step, chunk } = event.data
@@ -576,14 +695,14 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
       case 'tool/call': {
         this.openCalls.set(String(event.data.callId), {
           callId: String(event.data.callId), name: event.data.name, argsRaw: event.data.arguments,
-          turn: event.data.turn, step: event.data.step,
+          turn: event.data.turn, step: event.data.step, time: event.time,
           callView: view?.for === 'call' ? view.view : null,
         })
         this.callsRev++
         return
       }
       case 'tool/result': {
-        if (this.openCalls.delete(String(event.data.callId))) this.callsRev++
+        if (this.openCalls.delete(String(event.data.message.source.callId))) this.callsRev++
         return
       }
       case 'turn/end': {
@@ -597,7 +716,8 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
           if (visible) {
             // Fractional seq: strictly after every event of this turn (all < turn/end seq), before the next turn.
             this.frozenNodes.push({
-              kind: 'assistant', seq: event.seq - 0.9, turn: this.partial.turn, step: this.partial.step,
+              kind: 'assistant', seq: event.seq - 0.9, time: event.time,
+              turn: this.partial.turn, step: this.partial.step,
               blocks, interrupted: true,
             })
             this.frozenRev++
@@ -611,8 +731,10 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
           this.callsRev++
           // The spinner card becomes an interrupted terminal card (never vanishes mid-flow).
           this.frozenNodes.push({
-            kind: 'tool-result', seq: event.seq - 0.8 + callOffset++ * 0.01, callId,
+            kind: 'tool-result', seq: event.seq - 0.8 + callOffset++ * 0.01, time: event.time,
+            callId,
             call: { name: call.name, argsRaw: call.argsRaw },
+            callTime: call.time,
             content: [], isError: true, error: { name: 'Interrupted', code: 'interrupted' },
             callView: call.callView, resultView: null,
           })
@@ -634,6 +756,8 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     this.callsRev++
     this.frozenNodes = []
     this.frozenRev++
+    this.codeDispatches = new Map()
+    this.dispatchesRev++
     for (let i = 0; i < this.events.length; i++) {
       const event = this.events[i]
       /* v8 ignore next -- dense-array guard: i stays within events.length, so the undefined arm needs a sparse array no caller builds. */
@@ -666,22 +790,50 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
     if (this.pendingCache === null || this.pendingCache.rev !== this.pendingRev) {
       this.pendingCache = { rev: this.pendingRev, value: [...this.pending.values()] }
     }
+    if (this.dispatchesCache === null || this.dispatchesCache.rev !== this.dispatchesRev) {
+      this.dispatchesCache = { rev: this.dispatchesRev, value: new Map(this.codeDispatches) }
+    }
+    if (this.queueCache === null || this.queueCache.rev !== this.queueRev) {
+      this.queueCache = { rev: this.queueRev, value: this.queued.map(entry => entry.row) }
+    }
+    const partial = this.partial?.toPartial() ?? null
     return {
       sessionId: this.sessionId,
       nodes,
       foldDegraded: degraded,
-      partial: this.partial?.toPartial() ?? null,
+      partial,
       runningCalls: this.callsCache.value,
       pending: this.pendingCache.value,
+      codeDispatches: this.dispatchesCache.value,
+      queue: this.queueCache.value,
       running: this.running,
+      composerPhase: derivePhase(
+        nodes.length > 0 || partial !== null || this.running || this.pendingCache.value.length > 0,
+        this.promptAttempted,
+      ),
       removed: this.removed,
       openState: this.openState,
       openError: this.openError,
       hasMore: this.hasMore,
       loadingOlder: this.loadingOlder,
       promptError: this.promptError,
+      blank: this.blankBit,
       lastAgentError: this.lastAgentError,
-      goal: this.goal,
     }
   }
 }
+
+/**
+ * The composerPhase judgment — the single site that knows the predicate
+ * (consumers switch on the result, never re-derive). Monotone per session
+ * object: `hasContent` only grows within a window and `promptAttempted` is
+ * sticky, so blank → engaging → active never steps back; a failed first
+ * prompt stays engaging (retry semantics — see ComposerPhase).
+ * @param hasContent - any conversation material exists (nodes, partial, running turn, pending waits).
+ * @param promptAttempted - a prompt was initiated on this session object.
+ * @returns the derived phase.
+ */
+function derivePhase(hasContent: boolean, promptAttempted: boolean): ComposerPhase {
+  if (hasContent) return 'active'
+  return promptAttempted ? 'engaging' : 'blank'
+}

packages/client/runtime/src/client/slots.ts

@@ -1,22 +1,88 @@
 /**
- * SlotsService: cordis Service wrapper over the pure SlotCore (ui-slots).
- * Every mutation re-emits as the 'slots/changed' cordis event; define/register
- * run through the caller's ctx.effect so a plugin's registrations are
- * collected when its fiber unloads (cordis-native cascade).
+ * SlotsService: the cordis Service layer of the slot system over the pure
+ * SlotCore (ui-slots owns registration semantics, the declaration ledger,
+ * the load-time validations, and the unload cascade). This layer owns what
+ * needs the runtime: the 'slots/changed' event bridge, register through the
+ * caller's ctx.effect (fiber unload collects registrations), the renderer
+ * install seam (install()/renderSlot('root') + the SlotRendererHost face),
+ * and the store INSTANCE axis — handle x scope key -> create/cache, dropped
+ * with the last holding entry, session instances cleared (with persisted
+ * state) on scope death.
  */
 /* eslint-disable @typescript-eslint/no-redundant-type-constituents --
- * `keyof SlotMap & string` is the declare-merge key pattern: SlotMap is empty
- * in this compilation unit (intersection reads `never`) but consumers merge
- * keys in; the rule fires on the empty-map view, not on real redundancy. */
+ * `keyof SlotMap & string` is the declare-merge key pattern: SlotMap only
+ * holds this package's 'root' row in this compilation unit, but consumers
+ * merge keys in; the rule fires on the narrow-map view, not on real
+ * redundancy. */
 import { Service } from 'cordis'
 import type { Context } from 'cordis'
 import { SlotCore } from '@deepseek-ai/dsh-client-ui-slots'
-import type { ComposedProps, RegisterArgs, SlotComponent, SlotEntry, SlotEntryDef, SlotMap, SlotSpec } from '@deepseek-ai/dsh-client-ui-slots'
-import type { ClientContext } from './index.ts'
+import type {
+  OwnerOf, SlotEntryDef, SlotMap, SlotRenderer, SlotRendererHost,
+  SlotScope, SlotSpec, StoreDecl, StoredEntry, StoreInstanceLike,
+} from '@deepseek-ai/dsh-client-ui-slots'
 
-/** cordis Service wrapper over the pure SlotCore; mutations re-emit as 'slots/changed'. */
+declare module '@deepseek-ai/dsh-client-ui-slots' {
+  interface SlotMap {
+    /** The built-in render-tree root hole (seeded by SlotCore): rendered only by the shell, occupied by a layout entry. */
+    'root': { kind: 'single'; scope: 'root'; owner: RootOwnerProps }
+  }
+}
+
+/** Root owner share: the shell supplies nothing — the frame is inject-assembled. */
+export interface RootOwnerProps { children?: never }
+
+/** Instance key for root-scoped store records (session records key by session id, so the literal cannot collide). */
+const ROOT_INSTANCE_KEY = 'root'
+
+// FIXME(slot-parity): the engine's arbitrated persist extensions — create()
+// takes the scope key (per-session localStorage suffix) and instances expose
+// clearPersisted() — are not yet on ui-slots' StoreHandle/StoreInstanceLike;
+// these local structural faces bridge until fw-slots lifts them.
+
+/** Store handle face as the engine actually ships it (scope-key-aware create). */
+interface EngineStoreHandle { create(scopeKey?: string): EngineStoreInstance }
+
+/** Engine instance face: the host-contract shape plus persisted-state cleanup. */
+interface EngineStoreInstance extends StoreInstanceLike { clearPersisted(): void }
+
+/** Store axis record: one per live handle, dropped when the last holding entry unloads. */
+interface StoreAxisRecord {
+  /** Scope of the slot the handle mounted under (the core validated cross-scope conflicts). */
+  scope: SlotScope
+  /** Live registrations holding the handle. */
+  refs: number
+  /** Root scope: the single instance under {@link ROOT_INSTANCE_KEY}; session scope: one per session id. */
+  instances: Map<string, EngineStoreInstance>
+}
+
+/** Type-erased options view the implementation works with (the typed overloads proved the shares). */
+interface ErasedRegisterOptions {
+  name: string
+  children?: Record<string, SlotSpec<SlotEntryDef>>
+  store?: StoreDecl
+  inject?: (...args: never[]) => Record<string, unknown>
+  key?: string
+  id?: string
+  order?: number
+  label?: string
+  /** Chain-slot routing selector (pure; the core validates presence for chain targets). */
+  select?: (owner: never) => unknown
+  /** Chain-slot explicit ordering override (ascending; registration order otherwise). */
+  priority?: number
+  registrant?: string
+}
+
+/** Erased core call face (the service re-erases at its own boundary; the core's typed face targets end callers). */
+interface ErasedCore { register(options: object, component: unknown): () => void }
+
+/** cordis Service layer of the slot system; see the module doc for the split with SlotCore. */
 export class SlotsService extends Service {
   private readonly _core = new SlotCore()
+  /** Store-instance axis: handle -> mounted scope, refcount, resolved instances. */
+  private readonly _stores = new Map<EngineStoreHandle, StoreAxisRecord>()
+  private _renderer: SlotRenderer | undefined
+  private _host: SlotRendererHost | undefined
 
   /**
    * @param ctx - owning root context.
@@ -27,44 +93,92 @@ export class SlotsService extends Service {
   }
 
   /**
-   * Record a slot spec (delegates to SlotCore.define; disposal follows the caller's fiber).
-   * @param key - SlotMap key.
-   * @param spec - kind/scope spec.
-   * @returns disposer.
+   * The single registration API. The typed face IS the core's register
+   * (both overloads reused verbatim — one authority, no structural copy;
+   * see SlotCore.register for children declaration, store seat, inject
+   * face, load-time validation, and the unload cascade). This layer adds:
+   * disposal through the caller's ctx.effect (fiber unload = cascade),
+   * exclusive-factory minting (`store: createXxxStore` becomes a per-entry
+   * handle), the registrant diagnostics stamp, and store-instance lifecycle
+   * on the entry axis.
+   *
+   * Declared here, implemented by prototype assignment below the class: it
+   * MUST stay a prototype method (never an instance arrow) — the cordis
+   * service proxy binds `this.ctx` to the CALLER's context at call time,
+   * which is what routes the effect (and the unload cascade) into the
+   * caller's fiber. An arrow property would freeze `this` to the service's
+   * own root ctx and silently break per-plugin disposal.
    */
-  define<K extends keyof SlotMap & string>(key: K, spec: SlotSpec<SlotMap[K]>): () => void {
-    // eslint-disable-next-line @typescript-eslint/no-misused-promises -- synchronous cleanup; direct return preserves disposer identity
-    return this.ctx.effect(() => this._core.define(key, spec), 'slots.define()')
+  declare readonly register: SlotCore['register']
+
+  /**
+   * Install the shell's renderer (web-react's createSlotRenderer product).
+   * Boot-once: a second install throws. Runs through the caller's ctx.effect,
+   * so shell fiber unload uninstalls the renderer.
+   * @param renderer - the outlet machinery implementing SlotRenderer.
+   */
+  install(renderer: SlotRenderer): void {
+    if (this._renderer !== undefined) throw new Error('slot renderer already installed (install() is boot-once)')
+    this.ctx.effect(() => {
+      this._renderer = renderer
+      return () => {
+        if (this._renderer === renderer) this._renderer = undefined
+      }
+    }, 'slots.install()')
   }
 
   /**
-   * Contribute a component (delegates to SlotCore.register; disposal follows the caller's fiber).
-   * @param key - SlotMap key.
-   * @param component - contributed component.
-   * @param args - kind-shaped options (mandatory for keyed/list kinds); the
-   * inject factory's binding is pinned to ClientContext.
-   * @returns disposer.
+   * The single ctx-level render entry: the shell renders 'root'; every other
+   * key renders inside components through the props renderSlot face. All
+   * three guards are fail-loud boot-order checks, no fallback.
+   * @param key - must be 'root' (runtime-enforced for dynamically composed callers).
+   * @param owner - owner share for the root entry (the shell supplies {}).
+   * @returns the rendered root tree.
    */
-  register<K extends keyof SlotMap & string, I extends object = Record<string, unknown>>(
-    // Client-context registrations have exactly one ctx shape: pin Ctx to
-    // ClientContext so inject factories dot services without a cast.
-    key: K, component: SlotComponent<ComposedProps<K, NoInfer<I>>>,
-    ...args: RegisterArgs<SlotMap[K], I, ClientContext>): () => void {
-    // eslint-disable-next-line @typescript-eslint/no-misused-promises -- synchronous cleanup; direct return preserves disposer identity
-    return this.ctx.effect(() => this._core.register<K, I, ClientContext>(key, component, ...args), 'slots.register()')
+  renderSlot<K extends keyof SlotMap & string>(key: K, owner: OwnerOf<K>): ReturnType<SlotRenderer['renderRoot']> {
+    // Widened: in this package's own program SlotMap holds only 'root', which
+    // would fold the guard to constant-false; the check exists for plain-JS
+    // and cross-program callers where K is wider.
+    if ((key as string) !== 'root') {
+      throw new Error(`ctx-level renderSlot only renders 'root' (got "${key}"); child slots render through the component props face`)
+    }
+    if (this._renderer === undefined) {
+      throw new Error("slot renderer not installed — boot must call ctx.slots.install(createSlotRenderer()) before rendering 'root'")
+    }
+    if (this._core.entries('root').length === 0) {
+      throw new Error("'root' has no registration — a layout entry must register into 'root' before the shell renders it")
+    }
+    return this._renderer.renderRoot(this.hostFace(), owner)
   }
 
   /**
-   * Snapshot entries for a key.
-   * @param key - SlotMap key.
-   * @returns registered entries (stable reference between mutations).
+   * Drop the per-session store instances of a dead session (the sessions
+   * service calls this on scope teardown; root-scoped records are untouched).
+   * Persisted state goes with the session — a never-rendered dead session can
+   * still own keys from an earlier page load, so the instance is materialized
+   * transiently just to clear storage (no-op for unpersisted stores).
+   * @param sessionId - the torn-down session.
    */
-  entries<K extends keyof SlotMap & string>(key: K): readonly SlotEntry<SlotMap[K]>[] {
+  pruneStoreScope(sessionId: string): void {
+    for (const [handle, record] of this._stores) {
+      if (record.scope !== 'session') continue
+      const instance = record.instances.get(sessionId) ?? handle.create(sessionId)
+      instance.clearPersisted()
+      record.instances.delete(sessionId)
+    }
+  }
+
+  /**
+   * Snapshot entries for a key (render-erased view; stable reference between mutations).
+   * @param key - SlotMap key.
+   * @returns registered entries.
+   */
+  entries(key: keyof SlotMap & string): readonly StoredEntry[] {
     return this._core.entries(key)
   }
 
   /**
-   * Look up a defined spec.
+   * Look up a declared spec (register-declared or the built-in 'root').
    * @param key - SlotMap key.
    * @returns spec or undefined.
    */
@@ -72,15 +186,6 @@ export class SlotsService extends Service {
     return this._core.spec(key)
   }
 
-  /**
-   * Dynamic-key escape hatch for spec lookup (renderer-side string keys).
-   * @param key - candidate slot key.
-   * @returns wide-typed spec or undefined.
-   */
-  specDynamic(key: string): SlotSpec<SlotEntryDef> | undefined {
-    return this._core.specDynamic(key)
-  }
-
   /**
    * Subscribe to a key's registration changes (microtask-batched).
    * @param key - SlotMap key.
@@ -100,8 +205,111 @@ export class SlotsService extends Service {
     return this._core.getVersion(key)
   }
 
-  /** The wrapped pure core (web-react's scopedSlots outlet reads through this). */
-  get core(): SlotCore {
-    return this._core
+  /** Delegating registration path: factory minting + registrant stamp + core write + instance-axis bookkeeping. */
+  private _register(options: ErasedRegisterOptions, component: unknown): () => void {
+    // Exclusive stores pass the factory itself: minted here into a per-entry
+    // handle so the stored entry always carries a resolvable handle (the
+    // core's shared-handle scope pinning applies to it harmlessly).
+    const store = typeof options.store === 'function' ? options.store() : options.store
+    const registrant = options.registrant ?? (this.ctx.fiber as { name?: string } | undefined)?.name
+    const erased: ErasedRegisterOptions = {
+      ...options,
+      ...(store !== undefined ? { store } : {}),
+      ...(registrant !== undefined ? { registrant } : {}),
+    }
+    // Core write first: all load-time validation (undeclared target,
+    // duplicate declaration, kind conflicts, cross-scope handle) throws
+    // there before this layer commits anything.
+    const dispose = (this._core as unknown as ErasedCore).register(erased, component)
+    if (store !== undefined) {
+      // Register succeeded, so the target's spec is on the ledger.
+      const scope = (this._core.specDynamic(options.name) as SlotSpec<never>).scope
+      this._acquire(store, scope)
+    }
+    let disposed = false
+    return () => {
+      if (disposed) return
+      disposed = true
+      dispose()
+      if (store !== undefined) this._release(store)
+    }
+  }
+
+  /** Build once after both object-layer services mount; per-session provide bundles still resolve lazily. */
+  private hostFace(): SlotRendererHost {
+    if (this._host !== undefined) return this._host
+    const sessions = this.ctx.get('sessions')
+    if (sessions === undefined) {
+      throw new Error("renderSlot('root') before the sessions service mounted — boot order puts runtime apply first")
+    }
+    const workspaces = this.ctx.get('workspaces')
+    if (workspaces === undefined) {
+      throw new Error("renderSlot('root') before the workspaces service mounted — boot order puts runtime apply first")
+    }
+    this._host = {
+      subscribe: (key, fn) => this._core.subscribe(key, fn),
+      getVersion: key => this._core.getVersion(key),
+      entriesOf: key => this._core.entries(key),
+      specOf: key => this._core.specDynamic(key),
+      isLive: entry => this._core.isLive(entry),
+      storeOf: (entry, scopeKey) =>
+        entry.store === undefined ? undefined : this.resolveStore(entry.store as unknown as EngineStoreHandle, scopeKey),
+      sessions: {
+        list: sessions.list,
+        provideInfo: sessions.currentProvideInfo,
+      },
+      workspaces: { list: workspaces.list },
+    }
+    return this._host
+  }
+
+  /** Resolve (create or reuse) the store instance for a registered handle under a scope key. */
+  private resolveStore(handle: EngineStoreHandle, sessionId: string | undefined): StoreInstanceLike {
+    const record = this._stores.get(handle)
+    if (record === undefined) throw new Error('store handle is not registered (entry unloaded, or the handle never went through register)')
+    const key = record.scope === 'root' ? ROOT_INSTANCE_KEY : sessionId
+    if (key === undefined) throw new Error(`${record.scope} store resolution requires a session id`)
+    let instance = record.instances.get(key)
+    if (instance === undefined) {
+      // Session instances get the scope key (the engine suffixes the persist
+      // key per session); root instances stay keyless.
+      instance = record.scope === 'root' ? handle.create() : handle.create(key)
+      record.instances.set(key, instance)
+    }
+    return instance
+  }
+
+  /** Bind (or re-reference) a handle on the axis; cross-scope conflicts already threw in the core. */
+  private _acquire(handle: EngineStoreHandle, scope: SlotScope): void {
+    const record = this._stores.get(handle)
+    if (record === undefined) {
+      this._stores.set(handle, { scope, refs: 1, instances: new Map() })
+      return
+    }
+    record.refs += 1
+  }
+
+  /** Drop one reference; the last holder's unload drops the record (instances go with it — engine stores need no explicit dispose). */
+  private _release(handle: EngineStoreHandle): void {
+    const record = this._stores.get(handle)
+    /* v8 ignore next -- defensive: release only runs from a disposer whose
+     * register acquired the same handle, so the record must exist; kept so a
+     * future call site cannot underflow the axis. */
+    if (record === undefined) return
+    record.refs -= 1
+    if (record.refs === 0) this._stores.delete(handle)
   }
 }
+
+// register's implementation (prototype assignment pairs with the `declare`
+// inside the class — see its JSDoc for why it must live on the prototype).
+// Element access reaches the private _register legally and keeps it a
+// TS-visible read.
+;(SlotsService.prototype as { register: (options: object, component: unknown) => () => void }).register
+  = function register(this: SlotsService, rawOptions: object, component: unknown): () => void {
+    // The core's overloads proved the shares; the implementation works on
+    // the erased view (same pattern as the core's own implementation arm).
+    const options = rawOptions as ErasedRegisterOptions
+    // eslint-disable-next-line @typescript-eslint/no-misused-promises -- synchronous cleanup; direct return preserves disposer identity
+    return this.ctx.effect(() => this['_register'](options, component), 'slots.register()')
+  }

packages/client/runtime/src/client/workspaces/manager.ts

@@ -0,0 +1,289 @@
+/** Workspace baseline, incremental-frame, and unary-action owner. */
+
+import type {
+  HostFrame, IApiClient, RpcError, RpcRequest, RpcResult, SessionId, WorkspaceId, WorkspaceView,
+} from '@deepseek-ai/dsh-client-connection/client'
+import { transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
+import { mergeOrderedBaseline } from '../ordered-baseline.ts'
+import { Notifier } from '../sessions/notifier.ts'
+import { Workspace, type WorkspaceCreateInput } from './workspace.ts'
+
+/** Monotone workspace-list arrival lifecycle. */
+export type WorkspaceListPhase = 'pending' | 'ready'
+
+/** Immutable workspace-list snapshot. */
+export interface WorkspaceListSnapshot {
+  items: readonly WorkspaceView[]
+  state: 'idle' | 'loading' | 'error'
+  phase: WorkspaceListPhase
+  error: RpcError | null
+}
+
+type WorkspaceDelta =
+  | { type: 'upsert'; workspace: WorkspaceView }
+  | { type: 'remove'; workspaceId: WorkspaceId }
+
+/** Workspace object cluster driven by one list baseline and changed-frame upserts. */
+export class WorkspaceManager {
+  private items: Workspace[] = []
+  private itemViewsSource: readonly Workspace[] | null = null
+  private itemViewsCache: readonly WorkspaceView[] = []
+  private state: WorkspaceListSnapshot['state'] = 'idle'
+  private phase: WorkspaceListPhase = 'pending'
+  private error: RpcError | null = null
+  private inflight: Promise<void> | null = null
+  private refreshFrames: WorkspaceDelta[] | null = null
+  /**
+   * Ids this process has seen removed, kept for the connection's lifetime so
+   * a late changed frame or a stale baseline row cannot resurrect a deleted
+   * row. Correctness rests on Host ids never being reused (the registry mints
+   * a fresh `randomUUID` per record, including when the same directory is
+   * registered again) — a path-derived id scheme would turn these entries
+   * into permanent blindfolds and must clear them instead.
+   */
+  private readonly removedIds = new Set<WorkspaceId>()
+  private snapshotCache: WorkspaceListSnapshot
+  private readonly notifier = new Notifier(() => {
+    this.snapshotCache = this.buildSnapshot()
+  })
+
+  /** @param api - shared wire client. */
+  constructor(private readonly api: IApiClient) {
+    this.snapshotCache = this.buildSnapshot()
+  }
+
+  /**
+   * Refresh from workspace.list. The first successful response establishes
+   * Host order; later responses update membership and values without moving
+   * identities already visible to the client. Frames arriving during the RPC
+   * are replayed over its response.
+   * @returns the shared in-flight refresh.
+   */
+  refresh(): Promise<void> {
+    if (this.inflight !== null) return this.inflight
+    this.state = 'loading'
+    this.error = null
+    const established = this.itemViews()
+    const frames: WorkspaceDelta[] = []
+    this.refreshFrames = frames
+    this.notifier.markDirty()
+    this.inflight = (async () => {
+      try {
+        const { result } = await this.api.workspace.list({})
+        if (result.ok) {
+          let items = this.phase === 'pending'
+            ? result.value.items
+            : mergeOrderedBaseline(established, result.value.items, workspace => workspace.workspaceId)
+          items = items.filter(workspace => !this.removedIds.has(workspace.workspaceId))
+          for (const delta of frames) items = applyWorkspaceDelta(items, delta)
+          this.installViews(items)
+          this.state = 'idle'
+          this.phase = 'ready'
+        } else {
+          this.state = 'error'
+          this.error = result.error
+        }
+      } catch (error) {
+        this.state = 'error'
+        const folded = transportError<never>(error)
+        /* v8 ignore next -- transportError always returns the failure branch. */
+        this.error = folded.ok ? null : folded.error
+      } finally {
+        this.refreshFrames = null
+        this.inflight = null
+        this.notifier.markDirty()
+      }
+    })()
+    return this.inflight
+  }
+
+  /**
+   * Create or resolve a real Workspace, then publish its returned snapshot
+   * without waiting for the changed frame.
+   * @param input - name under workspaceRoot or an existing absolute path.
+   * @returns the wire result.
+   */
+  async create(input: WorkspaceCreateInput): Promise<RpcResult<{ workspace: WorkspaceView; created: boolean }>> {
+    const workspace = new Workspace(this.api, input)
+    const completion = workspace.materialize()
+    if (completion === undefined) throw new Error('a local Workspace must be materializable')
+    const result = await completion
+    if (result.ok) this.upsert(result.value.workspace, workspace)
+    return result
+  }
+
+  /**
+   * Rename a Workspace, then publish its returned snapshot without waiting
+   * for the changed frame.
+   * @param workspaceId - target workspace.
+   * @param title - new display title.
+   * @returns the wire result.
+   */
+  async rename(workspaceId: WorkspaceId, title: string): Promise<RpcResult<{ workspace: WorkspaceView }>> {
+    const { result } = await this.api.workspace.rename({ workspaceId, title })
+    if (result.ok) this.upsert(result.value.workspace)
+    return result
+  }
+
+  /**
+   * Delete a Workspace registration and remove its local projection from the
+   * unary response without waiting for the Host frame.
+   * @param workspaceId - target workspace.
+   * @returns the wire result.
+   */
+  async delete(workspaceId: WorkspaceId): Promise<RpcResult<{ deleted: true }>> {
+    const { result } = await this.api.workspace.delete({ workspaceId })
+    if (result.ok) this.remove(workspaceId, true)
+    return result
+  }
+
+  /**
+   * Move a session within its Workspace's manual order, then publish the
+   * returned snapshot without waiting for the changed frame.
+   * @param workspaceId - owning workspace.
+   * @param sessionId - accounted session to move.
+   * @param beforeSessionId - accounted anchor to insert before; omitted appends.
+   * @returns the wire result.
+   */
+  async insertSessionBefore(
+    workspaceId: WorkspaceId,
+    sessionId: SessionId,
+    beforeSessionId?: SessionId,
+  ): Promise<RpcResult<{ workspace: WorkspaceView }>> {
+    const { result } = await this.api.workspace.insertSessionBefore({
+      workspaceId, sessionId,
+      ...beforeSessionId === undefined ? {} : { beforeSessionId },
+    })
+    if (result.ok) this.upsert(result.value.workspace)
+    return result
+  }
+
+  /**
+   * Host-frame entry. Non-workspace frames are ignored so the runtime can
+   * fan one host stream out to both object managers.
+   * @param envelope - host stream envelope.
+   */
+  handleHostEnvelope(envelope: RpcRequest<HostFrame>): void {
+    if (envelope.payload.type === 'host/workspace-changed') this.upsert(envelope.payload.workspace)
+    else if (envelope.payload.type === 'host/workspace-removed') this.remove(envelope.payload.workspaceId)
+  }
+
+  /** Re-pull the baseline after each connection generation. */
+  handleConnected(): void {
+    void this.refresh()
+  }
+
+  /**
+   * Subscribe to workspace snapshot invalidation.
+   * @param listener - snapshot invalidation callback.
+   * @returns unsubscribe function.
+   */
+  subscribe(listener: () => void): () => void {
+    return this.notifier.subscribe(listener)
+  }
+
+  /**
+   * Read the cached workspace snapshot after flushing pending notifications.
+   * @returns the cached workspace snapshot.
+   */
+  getSnapshot(): WorkspaceListSnapshot {
+    this.notifier.ensureFresh()
+    return this.snapshotCache
+  }
+
+  private buildSnapshot(): WorkspaceListSnapshot {
+    return {
+      items: this.itemViews(),
+      state: this.state,
+      phase: this.phase,
+      error: this.error,
+    }
+  }
+
+  /** Upsert one Host view, optionally retaining the local object that materialized it. */
+  private upsert(view: WorkspaceView, identity?: Workspace): void {
+    if (this.removedIds.has(view.workspaceId)) return
+    this.refreshFrames?.push({ type: 'upsert', workspace: view })
+    const index = this.items.findIndex(item => item.getSnapshot().view?.workspaceId === view.workspaceId)
+    // Mutation responses and changed frames race (two carriers, no ordering):
+    // reject a snapshot strictly older than the installed projection so a
+    // late unary response cannot roll back a newer frame.
+    const installed = index === -1 ? undefined : this.items[index]?.getSnapshot().view
+    if (installed !== undefined && Date.parse(view.updatedAt) < Date.parse(installed.updatedAt)) return
+    if (identity !== undefined) {
+      this.items = index === -1
+        ? [identity, ...this.items]
+        : this.items.map((item, position) => position === index ? identity : item)
+    } else if (index === -1) {
+      this.items = [new Workspace(this.api, view), ...this.items]
+    } else {
+      this.items[index]?.adopt(view)
+      this.items = [...this.items]
+    }
+    this.notifier.markDirty()
+  }
+
+  /** Remove one id idempotently and retain a tombstone against late echoes. */
+  private remove(workspaceId: WorkspaceId, direct = false): void {
+    this.refreshFrames?.push({ type: 'remove', workspaceId })
+    this.removedIds.add(workspaceId)
+    const items = this.items.filter(item =>
+      item.getSnapshot().view?.workspaceId !== workspaceId)
+    if (items.length === this.items.length) {
+      // The Host frame may have removed the row first but left its batched
+      // notification pending. A successful unary echo still flushes that
+      // committed state before the user action resolves.
+      if (direct) this.notifier.notifyNow()
+      return
+    }
+    this.items = items
+    if (direct) this.notifier.notifyNow()
+    else this.notifier.markDirty()
+  }
+
+  private installViews(views: readonly WorkspaceView[]): void {
+    const existing = new Map(
+      this.items.flatMap((workspace) => {
+        const view = workspace.getSnapshot().view
+        return view === undefined ? [] : [[view.workspaceId, workspace] as const]
+      }),
+    )
+    const installed = new Map<WorkspaceView['workspaceId'], Workspace>()
+    for (const view of views) {
+      const duplicate = installed.get(view.workspaceId)
+      if (duplicate !== undefined) {
+        duplicate.adopt(view)
+        continue
+      }
+      const workspace = existing.get(view.workspaceId) ?? new Workspace(this.api, view)
+      workspace.adopt(view)
+      installed.set(view.workspaceId, workspace)
+    }
+    this.items = [...installed.values()]
+  }
+
+  private itemViews(): readonly WorkspaceView[] {
+    if (this.itemViewsSource === this.items) return this.itemViewsCache
+    this.itemViewsSource = this.items
+    this.itemViewsCache = this.items.flatMap((workspace) => {
+      const view = workspace.getSnapshot().view
+      return view === undefined ? [] : [view]
+    })
+    return this.itemViewsCache
+  }
+}
+
+/** Known ids retain their position; a newly created Workspace enters first. */
+function upsertWorkspace(items: readonly WorkspaceView[], workspace: WorkspaceView): WorkspaceView[] {
+  const index = items.findIndex(item => item.workspaceId === workspace.workspaceId)
+  return index === -1
+    ? [workspace, ...items]
+    : items.map((item, position) => position === index ? workspace : item)
+}
+
+/** Replay one ordered delta over a baseline: upsert in place, or drop the removed id. */
+function applyWorkspaceDelta(items: readonly WorkspaceView[], delta: WorkspaceDelta): WorkspaceView[] {
+  return delta.type === 'upsert'
+    ? upsertWorkspace(items, delta.workspace)
+    : items.filter(workspace => workspace.workspaceId !== delta.workspaceId)
+}

packages/client/runtime/src/client/workspaces/service.ts

@@ -0,0 +1,291 @@
+/** WorkspacesService projects the Workspace object manager for UI consumers. */
+
+import type { Context } from 'cordis'
+import type {
+  IApiClient, RpcError, SessionId, WorkspaceId, WorkspaceView,
+} from '@deepseek-ai/dsh-client-connection/client'
+import type { SnapshotStore } from '../contract/store.ts'
+import { createSnapshotStore } from '../contract/store.ts'
+import type { SessionsService } from '../sessions/service.ts'
+import { WorkspaceManager, type WorkspaceListPhase } from './manager.ts'
+
+/** Workspace list plus the two-baseline readiness and default-target projection. */
+export interface WorkspaceListState {
+  items: readonly WorkspaceView[]
+  state: 'idle' | 'loading' | 'error'
+  phase: WorkspaceListPhase
+  error: RpcError | null
+  /** True only after both workspace.list and session.list have succeeded. */
+  baselinesReady: boolean
+  /** Most recently active Workspace, derived without changing `items` order. */
+  recentWorkspaceId: WorkspaceId | undefined
+}
+
+/** Structured create failure for UI flows that distinguish Host business errors. */
+export class WorkspaceCreateError extends Error {
+  constructor(readonly rpcError: RpcError) {
+    super(`workspace create failed: ${rpcError.code}: ${rpcError.message}`)
+    this.name = 'WorkspaceCreateError'
+  }
+}
+
+/** Real Workspace object layer and Host actions. */
+export class WorkspacesService {
+  /** UI-facing immutable projection; the manager remains wire truth. */
+  readonly list: SnapshotStore<WorkspaceListState>
+  /** Workspace baseline and frame owner. */
+  private readonly manager: WorkspaceManager
+  /** In-flight blank-session creates keyed by workspace (connectWorkspace coalescing). */
+  private readonly connecting = new Map<WorkspaceId, Promise<SessionId>>()
+  /** Guards the runtime-owned one-shot initial-selection subscription. */
+  private initialSelectionStarted = false
+
+  /**
+   * @param ctx - client root context.
+   * @param api - shared wire client.
+   * @param sessions - lower-level Session service used for recency and blank-session reuse.
+   */
+  constructor(ctx: Context, private readonly api: IApiClient, private readonly sessions: SessionsService) {
+    this.manager = new WorkspaceManager(api)
+    this.list = createSnapshotStore<WorkspaceListState>({
+      items: [], state: 'idle', phase: 'pending', error: null,
+      baselinesReady: false, recentWorkspaceId: undefined,
+    })
+    this.manager.subscribe(() => { this.project() })
+    this.sessions.list.subscribe(() => { this.project() })
+    ctx.reflect.provide('workspaces', this, undefined)
+  }
+
+  /**
+   * Resolve the session a New Session flow lands in once this Workspace is
+   * chosen: reuse the workspace's existing blank session when one is in the
+   * list mirror, else create a fresh one on the host (`session.create` births
+   * the full Session+Agent — the client holds no intermediate state). The
+   * caller owns navigation: take the returned id to `sessions.open`.
+   * Resolution guarantee (both arms): the returned id is already in the list
+   * store and `sessions.binding(id)` resolves synchronously — draft hand-off
+   * may write the new scope's machine before opening.
+   * @param workspaceId - chosen Workspace (must be in the workspace list).
+   * @returns the reused or newly created session id.
+   */
+  async connectWorkspace(workspaceId: WorkspaceId): Promise<SessionId> {
+    const workspace = this.list.getSnapshot().items.find(item => item.workspaceId === workspaceId)
+    if (workspace === undefined) throw new Error(`workspaces.connectWorkspace: unknown workspace ${workspaceId}`)
+    // Coalesce concurrent connects: a create's summary lands without cwd
+    // until the host frame arrives, so a second call inside that window
+    // would miss the reuse scan and mint another hidden blank session.
+    const inflight = this.connecting.get(workspaceId)
+    if (inflight !== undefined) return inflight
+    // Reuse: blank && same canonical cwd (workspace.path is the host realpath
+    // canon; summary cwd is the session header passthrough of the same canon).
+    const sessions = this.sessions.list.getSnapshot()
+    for (const id of sessions.ids) {
+      const summary = sessions.byId[id]
+      if (summary !== undefined && summary.blank && summary.cwd === workspace.path) return summary.id
+    }
+    const attempt = this.sessions.create({ workspaceId })
+      .finally(() => { this.connecting.delete(workspaceId) })
+    this.connecting.set(workspaceId, attempt)
+    return attempt
+  }
+
+  /**
+   * Follow the first complete Workspace/Session baseline and select a default
+   * session exactly once. A restored current session wins; otherwise the most
+   * recent Workspace is connected (reusing or creating its blank session).
+   * Later explicit clears stay cleared instead of retriggering this startup
+   * policy. A failed connect may retry on the next baseline projection.
+   * @returns disposer for the baseline subscription; late work cannot navigate after disposal.
+   */
+  startInitialSelection(): () => void {
+    if (this.initialSelectionStarted) {
+      throw new Error('workspaces.startInitialSelection: already started')
+    }
+    this.initialSelectionStarted = true
+    let state: 'waiting' | 'connecting' | 'done' = 'waiting'
+    let disposed = false
+    const reconcile = (): void => {
+      if (disposed || state !== 'waiting') return
+      const workspace = this.list.getSnapshot()
+      if (!workspace.baselinesReady) return
+      const current = this.sessions.list.getSnapshot().current
+      const target = workspace.recentWorkspaceId
+      if (current !== undefined || target === undefined) {
+        state = 'done'
+        return
+      }
+      state = 'connecting'
+      void this.connectWorkspace(target).then(
+        (sessionId) => {
+          if (disposed) return
+          if (this.sessions.list.getSnapshot().current === undefined) {
+            this.sessions.open(sessionId)
+          }
+          state = 'done'
+        },
+        (reason: unknown) => {
+          if (disposed) return
+          state = 'waiting'
+          console.warn('initial workspace selection failed:', reason)
+        },
+      )
+    }
+    const unsubscribe = this.list.subscribe(reconcile)
+    reconcile()
+    return () => {
+      disposed = true
+      unsubscribe()
+    }
+  }
+
+  /**
+   * The shared New Session action behind the shell entry points (sidebar
+   * button, workspace browser): resolve the target Workspace — explicit wins,
+   * else the recent-Workspace projection — connect its blank session and
+   * navigate there; with no Workspace at all, clear the selection into the
+   * New Session view state. Connect failures are non-fatal (console
+   * diagnostics; the current view stays usable).
+   * @param workspaceId - explicit target Workspace for scoped actions.
+   */
+  startSession(workspaceId?: WorkspaceId): void {
+    const target = workspaceId ?? this.list.getSnapshot().recentWorkspaceId
+    if (target === undefined) {
+      this.sessions.clear()
+      return
+    }
+    void this.connectWorkspace(target).then(
+      (sessionId) => { this.sessions.open(sessionId) },
+      (reason: unknown) => { console.warn('new session failed:', reason) },
+    )
+  }
+
+  /**
+   * Create a Workspace by name or register an existing path.
+   * @param input - exactly one Host create spelling.
+   * @returns the created or idempotently resolved Workspace.
+   */
+  async create(input: { name: string } | { path: string }): Promise<WorkspaceView> {
+    const result = await this.manager.create(input)
+    if (!result.ok) throw new WorkspaceCreateError(result.error)
+    return result.value.workspace
+  }
+
+  /**
+   * Open the Host's native directory picker.
+   * @returns the selected path, or null when the user cancelled.
+   */
+  async pickDirectory(): Promise<string | null> {
+    const response = await this.api.host.pickDirectory({})
+    if (!response.result.ok) {
+      throw new Error(`directory picker failed: ${response.result.error.message}`)
+    }
+    return response.result.value.path
+  }
+
+  /**
+   * Open a filesystem path with the Host operating system's default application.
+   * @param path - absolute or host-resolvable path.
+   */
+  async openPath(path: string): Promise<void> {
+    const response = await this.api.host.openPath({ path })
+    if (!response.result.ok) {
+      throw new Error(`path open failed: ${response.result.error.message}`)
+    }
+  }
+
+  /**
+   * Rename a Workspace.
+   * @param workspaceId - target workspace.
+   * @param title - new display title (trimmed non-empty by the Host).
+   * @returns the renamed Workspace view.
+   */
+  async rename(workspaceId: WorkspaceId, title: string): Promise<WorkspaceView> {
+    const result = await this.manager.rename(workspaceId, title)
+    if (!result.ok) throw new Error(`workspace rename failed: ${result.error.code}: ${result.error.message}`)
+    return result.value.workspace
+  }
+
+  /**
+   * Delete one Workspace registration. Sessions, session logs, and the
+   * directory remain Host-owned outside this operation.
+   * @param workspaceId - target workspace.
+   */
+  async delete(workspaceId: WorkspaceId): Promise<void> {
+    const result = await this.manager.delete(workspaceId)
+    if (!result.ok) throw new Error(`workspace delete failed: ${result.error.code}: ${result.error.message}`)
+  }
+
+  /**
+   * Move a session within its Workspace's manual order (DOM-insertBefore-like).
+   * @param workspaceId - owning workspace.
+   * @param sessionId - accounted session to move.
+   * @param beforeSessionId - accounted anchor to insert before; omitted appends.
+   * @returns the updated Workspace view.
+   */
+  async insertSessionBefore(
+    workspaceId: WorkspaceId,
+    sessionId: SessionId,
+    beforeSessionId?: SessionId,
+  ): Promise<WorkspaceView> {
+    const result = await this.manager.insertSessionBefore(workspaceId, sessionId, beforeSessionId)
+    if (!result.ok) throw new Error(`workspace move failed: ${result.error.code}: ${result.error.message}`)
+    return result.value.workspace
+  }
+
+  /**
+   * Refresh the workspace baseline, reusing an in-flight pull.
+   * @returns completion of the current or newly started workspace baseline pull.
+   */
+  refresh(): Promise<void> {
+    return this.manager.refresh()
+  }
+
+  /**
+   * Route a Host stream envelope into the Workspace object layer.
+   * @param envelope - validated Host stream envelope.
+   */
+  handleHostEnvelope(envelope: Parameters<WorkspaceManager['handleHostEnvelope']>[0]): void {
+    this.manager.handleHostEnvelope(envelope)
+  }
+
+  /** Rebuild the Workspace baseline after connection. */
+  handleConnected(): void {
+    this.manager.handleConnected()
+  }
+
+  private project(): void {
+    const workspace = this.manager.getSnapshot()
+    const sessions = this.sessions.list.getSnapshot()
+    const baselinesReady = workspace.phase === 'ready' && sessions.phase === 'ready'
+    this.list.set({
+      items: workspace.items,
+      state: workspace.state,
+      phase: workspace.phase,
+      error: workspace.error,
+      baselinesReady,
+      recentWorkspaceId: baselinesReady ? recentWorkspace(workspace.items, sessions.byId) : undefined,
+    })
+  }
+}
+
+/** Stable tie-breaking follows Host Workspace order. */
+function recentWorkspace(
+  workspaces: readonly WorkspaceView[],
+  sessions: ReturnType<SessionsService['list']['getSnapshot']>['byId'],
+): WorkspaceId | undefined {
+  let selected: WorkspaceId | undefined
+  let selectedTime = Number.NEGATIVE_INFINITY
+  for (const workspace of workspaces) {
+    let latest = Number.NEGATIVE_INFINITY
+    for (const sessionId of workspace.sessionIds) {
+      const session = sessions[sessionId]
+      if (session !== undefined) latest = Math.max(latest, session.updatedAt)
+    }
+    if (latest === Number.NEGATIVE_INFINITY) latest = Date.parse(workspace.createdAt)
+    if (selected === undefined || latest > selectedTime) {
+      selected = workspace.workspaceId
+      selectedTime = latest
+    }
+  }
+  return selected
+}

packages/client/runtime/src/client/workspaces/workspace.ts

@@ -0,0 +1,143 @@
+/** React-free Workspace entity with a client-local materialization lifecycle. */
+
+import type {
+  IApiClient, RpcResult, WorkspaceView,
+} from '@deepseek-ai/dsh-client-connection/client'
+import { transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
+import type { ObservableSnapshot } from '../contract/store.ts'
+import { Notifier } from '../sessions/notifier.ts'
+
+/** Host input retained by a local Workspace until materialization succeeds. */
+export type WorkspaceCreateInput = { name: string } | { path: string }
+
+/** Observable state of a client-local Workspace intent. */
+export interface WorkspaceIntentSnapshot {
+  name: string
+  phase: 'ready' | 'creating'
+  error?: string
+}
+
+/** A Workspace is either a local intent or a materialized Host view. */
+export interface WorkspaceSnapshot {
+  view: WorkspaceView | undefined
+  intent: WorkspaceIntentSnapshot | undefined
+}
+
+interface WorkspaceIntent {
+  input: WorkspaceCreateInput
+  snapshot: WorkspaceIntentSnapshot
+}
+
+/**
+ * Observable Workspace object whose identity survives Host materialization.
+ * Local instances retain their create input and failure state; materialized
+ * instances expose the latest Host view.
+ */
+export class Workspace implements ObservableSnapshot<WorkspaceSnapshot> {
+  private view: WorkspaceView | undefined
+  private intent: WorkspaceIntent | undefined
+  private materialization: Promise<RpcResult<{ workspace: WorkspaceView; created: boolean }>> | null = null
+  private snapshotCache: WorkspaceSnapshot
+  private readonly notifier = new Notifier(() => {
+    this.snapshotCache = this.buildSnapshot()
+  })
+
+  /**
+   * @param api - shared wire client.
+   * @param source - local create input or an existing Host Workspace view.
+   */
+  constructor(private readonly api: IApiClient, source: WorkspaceCreateInput | WorkspaceView) {
+    if ('workspaceId' in source) {
+      this.view = source
+    } else {
+      this.intent = {
+        input: source,
+        snapshot: { name: intentName(source), phase: 'ready' },
+      }
+    }
+    this.snapshotCache = this.buildSnapshot()
+  }
+
+  /**
+   * Materialize this local Workspace through the Host create seam.
+   * Re-entry shares the in-flight completion; a materialized instance returns undefined.
+   * @returns the Host result, or undefined when this Workspace is already materialized.
+   */
+  materialize(): Promise<RpcResult<{ workspace: WorkspaceView; created: boolean }>> | undefined {
+    if (this.materialization !== null) return this.materialization
+    const intent = this.intent
+    if (intent === undefined) return undefined
+    intent.snapshot = { name: intent.snapshot.name, phase: 'creating' }
+    this.notifier.notifyNow()
+    const completion = this.completeMaterialization(intent).finally(() => {
+      if (this.materialization === completion) this.materialization = null
+    })
+    this.materialization = completion
+    return completion
+  }
+
+  /**
+   * Adopt a Host view without replacing this Workspace object.
+   * An existing materialized identity accepts updates only for the same Workspace id.
+   * @param view - latest Host projection.
+   */
+  adopt(view: WorkspaceView): void {
+    if (this.view !== undefined && this.view.workspaceId !== view.workspaceId) {
+      throw new Error('cannot adopt a different Workspace id')
+    }
+    this.view = view
+    this.intent = undefined
+    this.notifier.markDirty()
+  }
+
+  /**
+   * Subscribe to Workspace snapshot invalidation.
+   * @param listener - snapshot invalidation callback.
+   * @returns unsubscribe function.
+   */
+  subscribe(listener: () => void): () => void {
+    return this.notifier.subscribe(listener)
+  }
+
+  /**
+   * Read the cached Workspace snapshot after flushing pending notifications.
+   * @returns the cached Workspace snapshot.
+   */
+  getSnapshot(): WorkspaceSnapshot {
+    this.notifier.ensureFresh()
+    return this.snapshotCache
+  }
+
+  private async completeMaterialization(
+    intent: WorkspaceIntent,
+  ): Promise<RpcResult<{ workspace: WorkspaceView; created: boolean }>> {
+    let result: RpcResult<{ workspace: WorkspaceView; created: boolean }>
+    try {
+      result = (await this.api.workspace.create(intent.input)).result
+    } catch (error) {
+      result = transportError(error)
+    }
+    if (this.intent !== intent) return result
+    if (result.ok) {
+      this.adopt(result.value.workspace)
+    } else {
+      intent.snapshot = {
+        name: intent.snapshot.name,
+        phase: 'ready',
+        error: `${result.error.code}: ${result.error.message}`,
+      }
+      this.notifier.markDirty()
+    }
+    return result
+  }
+
+  private buildSnapshot(): WorkspaceSnapshot {
+    return { view: this.view, intent: this.intent?.snapshot }
+  }
+}
+
+function intentName(input: WorkspaceCreateInput): string {
+  if ('name' in input) return input.name
+  const trimmed = input.path.replace(/[\\/]+$/, '')
+  return trimmed.split(/[\\/]/).pop() ?? input.path
+}

packages/client/runtime/src/index.ts

@@ -1,11 +1,4 @@
-/**
- * Runtime plugin, node half. The implementation lives entirely in the client
- * half (src/client/ — SlotsService, SessionsService + object layer, and the
- * shell-held ClientLoader under ./loader); consumers import the /client or
- * /loader subpaths. The empty apply exists so the plugin appears in the host
- * Loader (lifecycle governance + dshClient discovery). Contract:
- * api-contracts v3 section 4.
- */
+/** Host loader entry for the browser runtime exported from `./client` and `./loader`. */
 
 /** Host plugin body — no host-side behavior for the runtime plugin. */
 export function apply(_ctx: unknown): void {}

packages/client/runtime/tests/client-apply.spec.ts

@@ -1,5 +1,5 @@
 /**
- * Runtime plugin browser-half apply: slots + sessions mounting over the
+ * Runtime plugin browser-half apply: slots + object services mounting over the
  * connection handle, stream-loop sink wiring into the object layer, and the
  * fiber-scoped loop teardown.
  */
@@ -8,7 +8,9 @@ import { describe, expect, it } from 'vitest'
 import type { ConnectionHandle } from '@deepseek-ai/dsh-client-connection/client'
 import type { ConnectionSinks } from '@deepseek-ai/dsh-client-connection/client'
 import * as RuntimeClient from '../src/client/index.ts'
-import { FakeApiClient } from './fake-api.ts'
+import type { SessionsService } from '../src/client/sessions/service.ts'
+import type { WorkspacesService } from '../src/client/workspaces/service.ts'
+import { FakeApiClient, ok } from './fake-api.ts'
 
 interface Bench {
   ctx: Context
@@ -33,26 +35,73 @@ async function mount(): Promise<Bench> {
   return bench
 }
 
+async function flushMicrotasks(): Promise<void> {
+  for (let i = 0; i < 12; i++) await Promise.resolve()
+}
+
 describe('runtime client apply', () => {
-  it('mounts ctx.slots + ctx.sessions and wires the stream sinks into the manager', async () => {
+  it('mounts slots, Sessions, and Workspaces and fans host frames into both managers', async () => {
     const bench = await mount()
     expect(bench.ctx.get('slots') !== undefined).toBe(true)
+    // The built-in 'root' declaration ships with this package's SlotsService
+    // (the SlotMap 'root' merge lives here since the slot-parity rework).
+    expect(bench.ctx.slots.spec('root')).toEqual({ kind: 'single', scope: 'root' })
     const sessions = bench.ctx.get('sessions')
+    const workspaces = bench.ctx.get('workspaces')
     expect(sessions !== undefined).toBe(true)
+    expect(workspaces !== undefined).toBe(true)
+    if (workspaces === undefined) throw new Error('WorkspacesService missing after runtime apply')
     expect(bench.sinks).toBeDefined()
 
     // Frame sinks reach the object layer: a host session-added lands in the list store.
     bench.sinks?.onHostEnvelope?.({
       rpcId: 'r1' as never,
-      payload: { type: 'host/session-added', sessionId: 's-new' } as never,
+      payload: { type: 'host/session-added', blank: true, sessionId: 's-new' } as never,
     })
     await Promise.resolve()
     expect((sessions as { list: { getSnapshot(): { ids: string[] } } }).list.getSnapshot().ids).toContain('s-new')
+    bench.sinks?.onHostEnvelope?.({
+      rpcId: 'r-workspace' as never,
+      payload: {
+        type: 'host/workspace-changed',
+        workspace: {
+          workspaceId: 'w-new', path: '/w/new', title: 'new', sessionIds: [],
+          createdAt: '2026-01-01T00:00:00.000Z', updatedAt: '2026-01-01T00:00:00.000Z',
+        },
+      } as never,
+    })
+    await Promise.resolve()
+    expect(workspaces.list.getSnapshot().items[0]?.workspaceId).toBe('w-new')
     // Mux sink and onConnected route without throwing (manager semantics own the behavior).
     bench.sinks?.onMuxEnvelope?.({ rpcId: 'r2' as never, payload: { type: 'stream/error', message: 'x' } as never })
     bench.sinks?.onConnected?.()
   })
 
+  it('selects the recent Workspace once when the first baselines have no current session', async () => {
+    const bench = await mount()
+    bench.api.onWorkspaceList = () => Promise.resolve(ok({
+      items: [{
+        workspaceId: 'w-recent', path: '/w/recent', title: 'recent', sessionIds: [],
+        createdAt: '2026-01-01T00:00:00.000Z', updatedAt: '2026-01-01T00:00:00.000Z',
+      }] as never[],
+    }))
+    bench.api.onList = () => Promise.resolve(ok({ items: [] }))
+
+    bench.sinks?.onConnected?.()
+    await flushMicrotasks()
+
+    const sessions = bench.ctx.get('sessions') as SessionsService
+    const workspaces = bench.ctx.get('workspaces') as WorkspacesService
+    expect(bench.api.callsOf('session.create')).toEqual([{ workspaceId: 'w-recent' }])
+    expect(sessions.list.getSnapshot().current).toBe('fk-new')
+
+    sessions.clear()
+    await workspaces.refresh()
+    await flushMicrotasks()
+    expect(sessions.list.getSnapshot().current).toBeUndefined()
+    expect(bench.api.callsOf('session.create')).toHaveLength(1)
+  })
+
   it('stops the stream loop when the plugin fiber unloads', async () => {
     const bench = await mount()
     const fiber = [...bench.ctx.registry.values()].find(f => f.name?.includes('client'))

packages/client/runtime/tests/client-loader-bundle.e2e.ts

@@ -1,77 +0,0 @@
-/**
- * Real-bundle smoke: the actual tsdown client bundle of ui-layout runs
- * through the loader chain (execute → handoff → factory(require) → apply →
- * export re-registration). Skips when the bundle is not built (lib/client.js is a
- * build product; `pnpm --filter @deepseek-ai/dsh-client-ui-layout build`).
- */
-import { readFileSync } from 'node:fs'
-import { createRequire } from 'node:module'
-import { Context } from 'cordis'
-import { afterEach, describe, expect, it } from 'vitest'
-import * as uiSlots from '@deepseek-ai/dsh-client-ui-slots'
-import * as webReact from '@deepseek-ai/dsh-client-web-react'
-import { createClientLoader } from '../src/client/loader/index.ts'
-import type { ClientPluginHandoff } from '../src/client/loader/index.ts'
-import { SessionsService } from '../src/client/sessions/service.ts'
-import { SlotsService } from '../src/client/slots.ts'
-import { FakeApiClient } from './fake-api.ts'
-
-const LAYOUT_ID = '@deepseek-ai/dsh-client-ui-layout'
-
-type Win = { DSHClientProxy?: { loadPlugin(h: ClientPluginHandoff): void }; window?: unknown }
-
-afterEach(() => {
-  delete (globalThis as Win).DSHClientProxy
-  delete (globalThis as Win).window
-})
-
-function readLayoutBundle(): string | undefined {
-  try {
-    const require = createRequire(import.meta.url)
-    return readFileSync(require.resolve(`${LAYOUT_ID}/client`), 'utf8')
-  } catch {
-    return undefined
-  }
-}
-
-describe('real tsdown bundle through the loader', () => {
-  const code = readLayoutBundle()
-
-  it.skipIf(code === undefined)('loads ui-layout lib/client.js: handoff, DI require, apply, export surface', async () => {
-    // The bundle banner addresses window.DSHClientProxy; node has no window —
-    // alias it to globalThis so the loader-installed proxy is reachable.
-    ;(globalThis as Win).window = globalThis
-    const ctx = new Context()
-    // The layout apply consumes the slots + sessions services; the real chain
-    // loads the runtime bundle first — stand both up directly here.
-    ctx.plugin(SlotsService)
-    await ctx.fiber.await()
-    new SessionsService(ctx, new FakeApiClient())
-    const loader = createClientLoader({
-      ctx,
-      // The real bundle externals resolved from the seeded table. React is a
-      // type-only import in the layout bundle today, but jsx-runtime is real.
-      modules: {
-        'react': await import('react'),
-        'react/jsx-runtime': await import('react/jsx-runtime'),
-        '@deepseek-ai/dsh-client-ui-slots': uiSlots,
-        '@deepseek-ai/dsh-client-web-react': webReact,
-      },
-      boot: { plugins: [{ id: LAYOUT_ID, url: `/plugins/${LAYOUT_ID}/client.js`, inject: [] }] },
-      fetchBundle: () => Promise.resolve(code as string),
-      // node has no DOM: evaluate the bundle body directly (same synchronous
-      // handoff contract as the <script> path).
-      executeBundle: (bundleCode) => {
-        // Node has no <script>: Function-evaluating the built bundle IS the
-        // system under test (same synchronous handoff as the browser path).
-        // eslint-disable-next-line @typescript-eslint/no-implied-eval, @typescript-eslint/no-unsafe-call
-        new Function(bundleCode)()
-      },
-    })
-    loader.start()
-    await loader.settled()
-    expect(loader.status.getSnapshot()[LAYOUT_ID]).toBe('active')
-    const surface = loader.requireModule(LAYOUT_ID) as Record<string, unknown>
-    expect(typeof surface.apply).toBe('function')
-  })
-})

packages/client/runtime/tests/client-loader.spec.ts

@@ -1,289 +0,0 @@
-/**
- * ClientLoader: handoff protocol (single slot, id reconciliation), DI require
- * with export-surface re-registration, immediately-group barrier (parallel
- * fetch / topology execution / full-group barrier), status store, settled,
- * failure modes (missing handoff, unknown dep, cycle, unload stub).
- */
-import { Context } from 'cordis'
-import { afterEach, describe, expect, it } from 'vitest'
-import { createClientLoader } from '../src/client/loader/index.ts'
-import type { BootPluginEntry, ClientPluginHandoff } from '../src/client/loader/index.ts'
-
-type Win = { DSHClientProxy?: { loadPlugin(h: ClientPluginHandoff): void }; __DSH_BOOT__?: { plugins: BootPluginEntry[] } }
-const win = globalThis as Win
-
-afterEach(() => {
-  delete win.DSHClientProxy
-  delete win.__DSH_BOOT__
-})
-
-interface FakeBundle {
-  handoff: ClientPluginHandoff | null | ((require: (spec: string) => unknown) => Record<string, unknown>)
-}
-
-interface Bench {
-  loader: ReturnType<typeof createClientLoader>
-  fetched: string[]
-  executed: string[]
-  fetchGate: Map<string, () => void>
-}
-
-/** Build a loader over scripted fake bundles keyed by url; fetches resolve when released (or immediately). */
-function bench(
-  plugins: BootPluginEntry[],
-  bundles: Record<string, FakeBundle>,
-  opts: { modules?: Record<string, unknown>; gated?: string[] } = {},
-): Bench {
-  const ctx = new Context()
-  const fetched: string[] = []
-  const executed: string[] = []
-  const fetchGate = new Map<string, () => void>()
-  const loader = createClientLoader({
-    ctx,
-    modules: opts.modules ?? { react: { marker: 'react' } },
-    boot: { plugins },
-    fetchBundle: (url) => {
-      fetched.push(url)
-      if (opts.gated?.includes(url) === true) {
-        return new Promise<string>((resolve) => { fetchGate.set(url, () => { resolve(url) }) })
-      }
-      return Promise.resolve(url)
-    },
-    executeBundle: (code) => {
-      executed.push(code)
-      const bundle = bundles[code]
-      if (bundle === undefined) throw new Error(`no fake bundle for ${code}`)
-      if (bundle.handoff === null) return // simulates a bundle that never calls loadPlugin
-      if (typeof bundle.handoff === 'function') {
-        win.DSHClientProxy?.loadPlugin({ id: code.replace('/client.js', '').replace('/plugins/', ''), factory: bundle.handoff })
-        return
-      }
-      win.DSHClientProxy?.loadPlugin(bundle.handoff)
-    },
-  })
-  return { loader, fetched, executed, fetchGate }
-}
-
-const entry = (id: string, inject: string[] = [], immediately?: boolean): BootPluginEntry =>
-  ({ id, url: `/plugins/${id}/client.js`, inject, ...(immediately === true ? { immediately: true } : {}) })
-
-const okBundle = (applied?: string[], exports: Record<string, unknown> = {}): FakeBundle => ({
-  handoff: require => ({
-    apply: (pluginCtx: Context) => { void pluginCtx; applied?.push('applied') },
-    require,
-    ...exports,
-  }),
-})
-
-describe('load chain', () => {
-  it('runs fetch→execute→handoff→factory(require)→apply→export re-registration→status active', async () => {
-    const applied: string[] = []
-    const b = bench(
-      [entry('fake-base', [], true), entry('feature', ['fake-base'])],
-      {
-        '/plugins/fake-base/client.js': { handoff: () => ({ apply: () => { applied.push('fake-base') }, helper: 'base-helper' }) },
-        '/plugins/feature/client.js': {
-          handoff: (require) => {
-            // Later loader requires the earlier one's export surface (inject topology guarantee).
-            const fakeBase = ['fake','base'].join('-') // assembled so knip's static require() scan skips the fake id
-            const base = require(fakeBase) as { helper: string }
-            expect(base.helper).toBe('base-helper')
-            expect((require('react') as { marker: string }).marker).toBe('react')
-            return { apply: () => { applied.push('feature') } }
-          },
-        },
-      },
-    )
-    b.loader.start()
-    await b.loader.settled()
-    expect(applied).toEqual(['fake-base', 'feature'])
-    expect(b.loader.status.getSnapshot()).toEqual({ 'fake-base': 'active', feature: 'active' })
-    expect((b.loader.requireModule('fake-base') as { helper: string }).helper).toBe('base-helper')
-    expect(() => b.loader.requireModule('ghost')).toThrow(/not available/)
-  })
-
-  it('fetches the immediately group in parallel and holds the barrier before the rest', async () => {
-    const b = bench(
-      [entry('a', [], true), entry('b', ['a'], true), entry('later')],
-      {
-        '/plugins/a/client.js': okBundle(),
-        '/plugins/b/client.js': okBundle(),
-        '/plugins/later/client.js': okBundle(),
-      },
-      { gated: ['/plugins/a/client.js'] },
-    )
-    b.loader.start()
-    await Promise.resolve()
-    // Both early fetches are in flight before any execution; the late plugin is not fetched yet.
-    expect(b.fetched).toEqual(['/plugins/a/client.js', '/plugins/b/client.js'])
-    expect(b.executed).toEqual([])
-    b.fetchGate.get('/plugins/a/client.js')?.()
-    await b.loader.settled()
-    expect(b.executed).toEqual(['/plugins/a/client.js', '/plugins/b/client.js', '/plugins/later/client.js'])
-  })
-
-  it('orders execution by inject topology within each group', async () => {
-    const b = bench(
-      [entry('z-ui', ['a-base']), entry('a-base')],
-      { '/plugins/a-base/client.js': okBundle(), '/plugins/z-ui/client.js': okBundle() },
-    )
-    b.loader.start()
-    await b.loader.settled()
-    expect(b.executed).toEqual(['/plugins/a-base/client.js', '/plugins/z-ui/client.js'])
-  })
-})
-
-describe('failure modes (fail loud)', () => {
-  it('rejects settled and marks failed when a bundle never calls loadPlugin', async () => {
-    const b = bench([entry('silent')], { '/plugins/silent/client.js': { handoff: null } })
-    b.loader.start()
-    await expect(b.loader.settled()).rejects.toThrow(/without calling DSHClientProxy.loadPlugin/)
-    expect(b.loader.status.getSnapshot().silent).toBe('failed')
-  })
-
-  it('rejects on manifest/handoff id mismatch', async () => {
-    const b = bench([entry('expected')], {
-      '/plugins/expected/client.js': { handoff: { id: 'imposter', factory: () => ({ apply: () => {} }) } },
-    })
-    b.loader.start()
-    await expect(b.loader.settled()).rejects.toThrow(/id mismatch/)
-  })
-
-  it('rejects unknown inject targets, cycles, missing apply, unknown load ids, duplicate manifest ids', async () => {
-    // Sequential benches: each loader owns the window proxy, so release it between them.
-    const fresh = <T>(build: () => T): T => {
-      delete win.DSHClientProxy
-      return build()
-    }
-
-    const missing = fresh(() => bench([entry('x', ['nope'])], { '/plugins/x/client.js': okBundle() }))
-    missing.loader.start()
-    await expect(missing.loader.settled()).rejects.toThrow(/injects unknown plugin "nope"/)
-
-    const cyclic = fresh(() => bench(
-      [entry('p', ['q']), entry('q', ['p'])],
-      { '/plugins/p/client.js': okBundle(), '/plugins/q/client.js': okBundle() },
-    ))
-    cyclic.loader.start()
-    await expect(cyclic.loader.settled()).rejects.toThrow(/inject cycle/)
-
-    const applyless = fresh(() => bench([entry('noap')], { '/plugins/noap/client.js': { handoff: { id: 'noap', factory: () => ({}) } } }))
-    applyless.loader.start()
-    await expect(applyless.loader.settled()).rejects.toThrow(/exports no apply/)
-
-    const b = fresh(() => bench([entry('a')], { '/plugins/a/client.js': okBundle() }))
-    await expect(b.loader.load('ghost')).rejects.toThrow(/unknown plugin "ghost"/)
-
-    expect(() => fresh(() => bench([entry('dup'), entry('dup')], {}))).toThrow(/duplicate manifest id/)
-  })
-
-  it('throws on missing boot manifest, double proxy install, and pre-start settled', () => {
-    expect(() => createClientLoader({ ctx: new Context(), modules: {} })).toThrow(/no boot manifest/)
-    const b = bench([], {})
-    expect(() => b.loader.settled()).toThrow(/settled\(\) before start\(\)/)
-    // First bench installed the proxy; a second loader must refuse.
-    expect(() => createClientLoader({ ctx: new Context(), modules: {}, boot: { plugins: [] } })).toThrow(/already installed/)
-  })
-
-  it('direct load() before a dependency is active fails loud (same check start() sequences)', async () => {
-    const b = bench(
-      [entry('dep', [], true), entry('needy', ['dep'])],
-      { '/plugins/dep/client.js': okBundle(), '/plugins/needy/client.js': okBundle() },
-    )
-    await expect(b.loader.load('needy')).rejects.toThrow(/loaded before its dependency "dep" is active/)
-  })
-
-  it('direct load() naming an unknown inject target fails loud', async () => {
-    const b = bench([entry('solo', ['phantom'])], { '/plugins/solo/client.js': okBundle() })
-    await expect(b.loader.load('solo')).rejects.toThrow(/injects unknown plugin "phantom"/)
-  })
-
-  it('an immediately-group fetch failure surfaces through settled, not as an unhandled prefetch rejection', async () => {
-    // The fire-and-forget prefetch swallow arm must absorb the early
-    // rejection; the awaited load surfaces the same failure via settled().
-    const ctx = new Context()
-    delete win.DSHClientProxy
-    const loader = createClientLoader({
-      ctx,
-      modules: {},
-      boot: { plugins: [{ id: 'kaboom', url: '/plugins/kaboom/client.js', inject: [], immediately: true }] },
-      fetchBundle: () => Promise.reject(new Error('bundle fetch exploded')),
-      executeBundle: () => {},
-    })
-    loader.start()
-    await expect(loader.settled()).rejects.toThrow(/bundle fetch exploded/)
-  })
-
-  it('unload is the P-I stub', async () => {
-    const b = bench([], {})
-    await expect(b.loader.unload('x')).rejects.toThrow(/not implemented/)
-  })
-})
-
-describe('DOM default seams (stubbed globals)', () => {
-  it('default fetchBundle uses fetch, rejects non-OK; default executeBundle injects an inline script; claimStyles tags orphans', async () => {
-    const origFetch = globalThis.fetch
-    const appended: { textContent?: string | null }[] = []
-    const styleTag = {
-      attrs: {} as Record<string, string>,
-      setAttribute(k: string, v: string) { this.attrs[k] = v },
-    }
-    const fakeDoc = {
-      createElement: () => {
-        const el = { textContent: null as string | null }
-        return el
-      },
-      head: { appendChild: (el: { textContent?: string | null }) => { appended.push(el) } },
-      querySelectorAll: () => [styleTag],
-    }
-    const g = globalThis as { document?: unknown; fetch: typeof fetch }
-    g.document = fakeDoc
-    g.fetch = (url: URL | RequestInfo) => Promise.resolve(
-      (typeof url === 'string' ? url : url instanceof URL ? url.href : url.url).includes('bad')
-        ? new Response('x', { status: 500 })
-        : new Response('window.DSHClientProxy.loadPlugin(globalThis.__seamHandoff)', { status: 200 }),
-    )
-    try {
-      delete win.DSHClientProxy
-      const ctx = new Context()
-      const loader = createClientLoader({
-        ctx,
-        modules: {},
-        boot: { plugins: [
-          { id: 'seam-ok', url: '/plugins/seam-ok/client.js', inject: [] },
-          { id: 'seam-bad', url: '/plugins/bad/client.js', inject: [] },
-        ] },
-        // NO seams injected (keys omitted, not undefined — exactOptional):
-        // the DOM defaults are under test.
-      })
-      const seamHandoff: ClientPluginHandoff = {
-        id: 'seam-ok',
-        factory: () => ({ apply: () => {} }),
-      }
-      // Default executeBundle only APPENDS the script element (no execution in
-      // our fake DOM), so drive the handoff manually before load resolves it.
-      const loadOk = loader.load('seam-ok')
-      await Promise.resolve()
-      ;(globalThis as Win).DSHClientProxy?.loadPlugin(seamHandoff)
-      await loadOk
-      expect(appended).toHaveLength(1)
-      expect(appended[0]?.textContent).toContain('sourceURL=/plugins/seam-ok/client.js')
-      expect(styleTag.attrs['data-plugin']).toBe('seam-ok')
-      await expect(loader.load('seam-bad')).rejects.toThrow(/answered 500/)
-    } finally {
-      g.fetch = origFetch
-      delete (globalThis as { document?: unknown }).document
-    }
-  })
-})
-
-describe('handoff slot protocol', () => {
-  it('rejects an overlapping loadPlugin before the loader claims the pending handoff', () => {
-    delete win.DSHClientProxy
-    createClientLoader({ ctx: new Context(), modules: {}, boot: { plugins: [] } })
-    const proxy = (globalThis as Win).DSHClientProxy
-    proxy?.loadPlugin({ id: 'first', factory: () => ({ apply: () => {} }) })
-    expect(() => proxy?.loadPlugin({ id: 'second', factory: () => ({ apply: () => {} }) }))
-      .toThrow(/overlapping loadPlugin handoff/)
-  })
-})

packages/client/runtime/tests/event-script.ts

@@ -1,3 +1,4 @@
+import { createUserMessage, createMessage, createToolResultMessage, CallId } from '@deepseek-ai/dsh-llm'
 // Minimal SessionEvent builders for orchestration tests (shape mirrors what the
 // host emits; only the fields the object layer reads).
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
@@ -13,7 +14,9 @@ export const ev = {
   turnStart: (seq: number, turn: number): SessionEvent =>
     at(seq, { type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } }),
   user: (seq: number, body: string): SessionEvent =>
-    at(seq, { type: 'user/message', surfaceOp: 'append', data: { content: text(body), source: { kind: 'user' } } }),
+    at(seq, { type: 'user/message', surfaceOp: 'append', data: createUserMessage({
+      content: text(body), source: { kind: 'user' },
+    }) }),
   stepStart: (seq: number, turn: number, step = 0): SessionEvent =>
     at(seq, { type: 'step/start', data: { turn, step } }),
   chunkStart: (seq: number, turn: number, step = 0, index = 0): SessionEvent =>
@@ -21,15 +24,51 @@ export const ev = {
   chunkText: (seq: number, turn: number, piece: string, step = 0, index = 0): SessionEvent =>
     at(seq, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'text-delta', index, text: piece } } }),
   assistant: (seq: number, turn: number, body: string, step = 0): SessionEvent =>
-    at(seq, { type: 'assistant/message', surfaceOp: 'append', data: { turn, step, content: text(body), provenance: { provider: 'fake', model: 'fk-1' } } }),
+    at(seq, { type: 'assistant/message', surfaceOp: 'append', data: {
+      turn, step,
+      message: createMessage({
+        role: 'assistant',
+        content: text(body),
+        source: {
+          kind: 'model',
+          ...{ provider: 'fake', model: 'fk-1' },
+        },
+      }),
+    } }),
   toolCall: (seq: number, turn: number, callId: string, name: string, args: string, step = 0): SessionEvent =>
     at(seq, { type: 'tool/call', data: { turn, step, callId, name, arguments: args } }),
   toolResult: (seq: number, turn: number, callId: string, body: string, step = 0): SessionEvent =>
-    at(seq, { type: 'tool/result', surfaceOp: 'append', data: { turn, step, callId, content: text(body), isError: false } }),
+    at(seq, {
+      type: 'tool/result',
+      surfaceOp: 'append',
+      data: {
+        turn,
+        step,
+        message: createToolResultMessage({
+          callId: CallId(callId),
+          content: text(body),
+          isError: false,
+        }),
+      },
+    }),
+  codeDispatchStart: (seq: number, parentCallId: string, n: number, name: string, args: unknown): SessionEvent =>
+    at(seq, {
+      type: 'tool/code-dispatch-start',
+      data: { parentCallId, subCallId: `${parentCallId}:code:${n}`, name, arguments: args },
+    }),
+  codeDispatch: (seq: number, parentCallId: string, n: number, name: string, args: unknown, body: string, isError = false): SessionEvent =>
+    at(seq, {
+      type: 'tool/code-dispatch',
+      data: { parentCallId, subCallId: `${parentCallId}:code:${n}`, name, arguments: args, isError, content: text(body) },
+    }),
   stepEnd: (seq: number, turn: number, step = 0): SessionEvent =>
     at(seq, { type: 'step/end', data: { turn, step } }),
   turnEnd: (seq: number, turn: number, reason: 'completed' | 'cancelled' = 'completed'): SessionEvent =>
     at(seq, { type: 'turn/end', data: { turn, reason: { kind: reason } } }),
+  commandRun: (seq: number, commandId: string, name: string, args = ''): SessionEvent =>
+    at(seq, { type: 'command/run', data: { commandId, name, args, source: { kind: 'user' } } }),
+  commandDone: (seq: number, commandId: string, kind: 'success' | 'error' = 'success', text?: string): SessionEvent =>
+    at(seq, { type: 'command/done', data: { commandId, kind, ...text === undefined ? {} : { text } } }),
 }
 
 /** One complete plain turn (turn/start → user → step → assistant → turn/end), 6 events from startSeq. */

packages/client/runtime/tests/fake-api.ts

@@ -1,11 +1,27 @@
 // Test-local programmable IApiClient fake (NOT the fixture: fixture is a demo
 // data source on a real clock; behavior tests need per-case responses and
 // deferred-controlled timing). Streams are hand pumps: pushMux/pushHost.
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type {
-  HostFrame, IApiClient, MuxFrame, RpcError, RpcRequest, RpcResponse, SessionId,
+  ClientResponse, CommandDescriptor, HostFrame, IApiClient, ModelTarget, MuxFrame,
+  RpcError, RpcReceipt, RpcRequest, RpcResponse, SessionId, SessionModels, SkillEntry,
+  WorkspaceId, WorkspaceView,
 } from '@deepseek-ai/dsh-client-connection/client'
 import { RpcId } from '@deepseek-ai/dsh-client-connection/client'
 
+/** Programmable-default workspace row (branded id, ISO-ish times). */
+function fakeWorkspace(id: string, over: Partial<WorkspaceView> = {}): WorkspaceView {
+  return {
+    workspaceId: id as WorkspaceId,
+    path: '/f/ws',
+    title: 'ws',
+    sessionIds: [],
+    createdAt: '2026-01-01T00:00:00.000Z',
+    updatedAt: '2026-01-01T00:00:00.000Z',
+    ...over,
+  }
+}
+
 export interface Deferred<T> {
   promise: Promise<T>
   resolve(value: T): void
@@ -46,14 +62,31 @@ export class FakeApiClient implements IApiClient {
   // Programmable slots (defaults answer OK-empty); reassign per case.
   onList: (payload: unknown) => Promise<RpcResponse<{ items: never[] }>> = () => Promise.resolve(ok({ items: [] }))
   onCreate: (payload: unknown) => Promise<RpcResponse<{ sessionId: SessionId }>> = () => Promise.resolve(ok({ sessionId: 'fk-new' as SessionId }))
+  readonly defaultModel: ModelTarget = { provider: 'deepseek', model: 'deepseek-v4-flash' }
   onHistory: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number })
   => Promise<RpcResponse<{ events: never[]; hasMore: boolean }>> =
     () => Promise.resolve(ok({ events: [], hasMore: false }))
 
+  onModels: (payload: unknown) => Promise<RpcResponse<SessionModels>> = () => Promise.resolve(ok({
+    current: this.defaultModel,
+    groups: [{
+      id: 'deepseek',
+      name: 'DeepSeek',
+      models: [{ id: 'deepseek-v4-flash', name: 'DeepSeek V4 Flash' }],
+    }],
+    failures: [],
+  }))
+  onSelectModel: (payload: { provider: string; model: string }) =>
+  Promise<RpcResponse<{ selected: ModelTarget }>> =
+    payload => Promise.resolve(ok({ selected: { provider: payload.provider, model: payload.model } }))
   onPrompt: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
   onCancel: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
   onDescribe: (payload: unknown) => Promise<RpcResponse<{ version: string; cwd: string; attachedSessions: number }>> =
     () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0 }))
+  onPickDirectory: (payload: unknown) => Promise<RpcResponse<{ path: string | null }>> =
+    () => Promise.resolve(ok({ path: null }))
+  onOpenPath: (payload: unknown) => Promise<RpcResponse<{ opened: true }>> =
+    () => Promise.resolve(ok({ opened: true as const }))
 
   private readonly muxConns: StreamConn<MuxFrame>[] = []
   private readonly hostConns: StreamConn<HostFrame>[] = []
@@ -66,16 +99,61 @@ export class FakeApiClient implements IApiClient {
     create: (payload: unknown) => this.record('session.create', payload, this.onCreate(payload)),
     history: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number }) =>
       this.record('session.history', payload, this.onHistory(payload)),
+    models: (payload: unknown) => this.record('session.models', payload, this.onModels(payload)),
+    selectModel: (payload: { provider: string; model: string }) =>
+      this.record('session.selectModel', payload, this.onSelectModel(payload)),
     prompt: (payload: unknown) => this.record('session.prompt', payload, this.onPrompt(payload)),
     cancel: (payload: unknown) => this.record('session.cancel', payload, this.onCancel(payload)),
   }
 
   readonly host: IApiClient['host'] = {
     describe: (payload: unknown) => this.record('host.describe', payload, this.onDescribe(payload)),
+    pickDirectory: (payload: unknown) => this.record('host.pickDirectory', payload, this.onPickDirectory(payload)),
+    openPath: (payload: unknown) => this.record('host.openPath', payload, this.onOpenPath(payload)),
+  }
+
+  onWorkspaceList: (payload: unknown) => Promise<RpcResponse<{ items: never[] }>> = () => Promise.resolve(ok({ items: [] }))
+  onWorkspaceCreate: (payload: unknown) => Promise<RpcResponse<{ workspace: WorkspaceView; created: boolean }>> =
+    () => Promise.resolve(ok({ workspace: fakeWorkspace('fk-ws'), created: true }))
+
+  onWorkspaceRename: (payload: unknown) => Promise<RpcResponse<{ workspace: WorkspaceView }>> =
+    () => Promise.resolve(ok({ workspace: fakeWorkspace('fk-ws') }))
+
+  onWorkspaceDelete: (payload: unknown) => Promise<RpcResponse<{ deleted: true }>> =
+    () => Promise.resolve(ok({ deleted: true }))
+
+  onWorkspaceInsertSessionBefore: (payload: unknown) => Promise<RpcResponse<{ workspace: WorkspaceView }>> =
+    () => Promise.resolve(ok({ workspace: fakeWorkspace('fk-ws') }))
+
+  readonly workspace: IApiClient['workspace'] = {
+    list: (payload: unknown) => this.record('workspace.list', payload, this.onWorkspaceList(payload)),
+    create: (payload: unknown) => this.record('workspace.create', payload, this.onWorkspaceCreate(payload)),
+    rename: (payload: unknown) => this.record('workspace.rename', payload, this.onWorkspaceRename(payload)),
+    delete: (payload: unknown) => this.record('workspace.delete', payload, this.onWorkspaceDelete(payload)),
+    insertSessionBefore: (payload: unknown) =>
+      this.record('workspace.insertSessionBefore', payload, this.onWorkspaceInsertSessionBefore(payload)),
+  }
+
+  // Payloads stay `unknown` (lint-lane note above); response rows are the real
+  // wire shapes so cases can program requires-bearing catalogs and dual-address
+  // skill lists without casts.
+  onCommandList: (payload: unknown) => Promise<RpcResponse<{ commands: CommandDescriptor[] }>>
+    = () => Promise.resolve(ok({ commands: [] }))
+  onCommandExecute: (payload: unknown) => Promise<RpcResponse<{ matched: boolean; commandId?: CommandId }>>
+    = () => Promise.resolve(ok({ matched: false }))
+  onSkillList: (payload: unknown) => Promise<RpcResponse<{ skills: SkillEntry[] }>>
+    = () => Promise.resolve(ok({ skills: [] }))
+
+  readonly commands: IApiClient['commands'] = {
+    list: (payload: unknown) => this.record('command.list', payload, this.onCommandList(payload)),
+    execute: (payload: unknown) => this.record('command.execute', payload, this.onCommandExecute(payload)),
+  }
+
+  readonly skills: IApiClient['skills'] = {
+    list: (payload: unknown) => this.record('skill.list', payload, this.onSkillList(payload)),
   }
 
   readonly goals: IApiClient['goals'] = {
-    get: payload => this.record('goal.get', payload, Promise.resolve(ok({ goal: null }))),
     create: payload => this.record('goal.create', payload, Promise.resolve(ok({ goal: null as unknown as never }))),
     edit: payload => this.record('goal.edit', payload, Promise.resolve(ok({ goal: null as unknown as never }))),
     pause: payload => this.record('goal.pause', payload, Promise.resolve(ok({ goal: null as unknown as never }))),
@@ -103,8 +181,10 @@ export class FakeApiClient implements IApiClient {
     host: (_payload: unknown, signal: AbortSignal, onOpen?: () => void) => this.openStream(this.hostConns, signal, onOpen),
   }
 
-  respond(): Promise<{ accepted: false; reason: 'not-pending' }> {
-    return Promise.resolve({ accepted: false, reason: 'not-pending' })
+  onRespond: (message: ClientResponse) => Promise<RpcReceipt> = () => Promise.resolve({ accepted: true })
+
+  respond(message: ClientResponse): Promise<RpcReceipt> {
+    return this.record('respond', message, this.onRespond(message))
   }
 
   /** Push one mux frame to every open mux stream (rpcId minted unless pinned by the case). */

packages/client/runtime/tests/fold-adapter.spec.ts

@@ -1,3 +1,4 @@
+import { createUserMessage, CallId, createMessage, createToolResultMessage } from '@deepseek-ai/dsh-llm'
 /**
  * FoldAdapter over the real core SurfaceManager: padding sentinels for paged
  * windows, incremental append with node-cache identity, six-variant
@@ -39,8 +40,16 @@ describe('FoldAdapter', () => {
     const events = [
       ev.user(0, '用户'),
       ev.assistant(1, 0, '助手'),
-      at(2, { type: 'steering/message', surfaceOp: 'append', data: { turn: 0, content: [{ type: 'text', text: '插话' }], source: { kind: 'user' } } }),
-      at(3, { type: 'context/message', surfaceOp: 'append', data: { content: [{ type: 'text', text: '上下文' }], source: { kind: 'plugin', plugin: 'p' } } }),
+      at(2, { type: 'steering/message', surfaceOp: 'append', data: {
+        turn: 0,
+        message: createUserMessage({
+          content: [{ type: 'text', text: '插话' }],
+          source: { kind: 'user' },
+        }),
+      } }),
+      at(3, { type: 'user/message', surfaceOp: 'append', data: createUserMessage({
+        content: [{ type: 'text', text: '上下文' }], source: { kind: 'plugin', plugin: 'p' },
+      }) }),
       ev.toolCall(4, 0, 'c1', 'echo', '{"x":1}'),
       ev.toolResult(5, 0, 'c1', '结果'),
     ]
@@ -76,7 +85,17 @@ describe('FoldAdapter', () => {
     // An invalid surfaceOp on a surface-eligible event deterministically throws in the core fold.
     const window = [
       ev.user(10, '正常'),
-      at(11, { type: 'assistant/message', surfaceOp: 'bogus-op', data: { turn: 0, step: 0, content: [{ type: 'text', text: '坏 op' }], provenance: { provider: 'x', model: 'y' } } }),
+      at(11, { type: 'assistant/message', surfaceOp: 'bogus-op', data: {
+        turn: 0, step: 0,
+        message: createMessage({
+          role: 'assistant',
+          content: [{ type: 'text', text: '坏 op' }],
+          source: {
+            kind: 'model',
+            ...{ provider: 'x', model: 'y' },
+          },
+        }),
+      } }),
     ]
     const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
     try {
@@ -98,7 +117,15 @@ describe('FoldAdapter', () => {
   it('materializes a tool-result error field when present', () => {
     const adapter = new FoldAdapter()
     adapter.reset([
-      at(0, { type: 'tool/result', surfaceOp: 'append', data: { turn: 0, step: 0, callId: 'c1', content: [], isError: true, error: { name: 'Boom', code: 'boom' } } }),
+      at(0, { type: 'tool/result', surfaceOp: 'append', data: {
+        turn: 0, step: 0,
+        message: createToolResultMessage({
+          callId: CallId('c1'),
+          content: [],
+          isError: true,
+        }),
+        error: { name: 'Boom', code: 'boom' },
+      } }),
     ], 0)
     expect(adapter.nodes().nodes[0]).toMatchObject({ kind: 'tool-result', isError: true, error: { code: 'boom' } })
   })
@@ -142,4 +169,83 @@ describe('FoldAdapter', () => {
     const node = adapter.nodes().nodes[0]
     expect(node).toMatchObject({ kind: 'tool-result', call: null, callView: null, resultView: { title: '孤儿' } })
   })
+
+  describe('command lifecycle nodes', () => {
+    it('folds a run/done pair into one settled node merged into flow order by seq', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([
+        ev.user(0, '先说话'),
+        ev.commandRun(1, 'cmd-1', 'plan'),
+        ev.commandDone(2, 'cmd-1', 'success', '已进入 plan mode'),
+        ev.assistant(3, 0, '然后回答'),
+      ], 0)
+      const { nodes } = adapter.nodes()
+      expect(nodes.map(n => [n.kind, n.seq])).toEqual([['user', 0], ['command', 1], ['assistant', 3]])
+      expect(nodes[1]).toMatchObject({
+        kind: 'command', commandId: 'cmd-1', name: 'plan', args: '',
+        outcome: { kind: 'success', text: '已进入 plan mode' },
+      })
+    })
+
+    it('renders a run with no done as still executing (outcome null)', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([ev.commandRun(0, 'cmd-2', 'goal', ' ship it')], 0)
+      expect(adapter.nodes().nodes[0]).toMatchObject({
+        kind: 'command', name: 'goal', args: ' ship it', outcome: null,
+      })
+    })
+
+    it('soft-falls a done-only window into a node built from the done (cross-window cut)', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([ev.commandDone(80, 'cmd-3', 'error', '失败了')], 80)
+      expect(adapter.nodes().nodes[0]).toMatchObject({
+        kind: 'command', seq: 80, commandId: 'cmd-3', name: null, args: null,
+        outcome: { kind: 'error', text: '失败了' },
+      })
+    })
+
+    it('settles a live-appended done in place, keeping the node at the run seq', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset(plainTurn(0, 0, 'q', 'a'), 0)
+      adapter.append(ev.commandRun(6, 'cmd-4', 'clear'))
+      const running = adapter.nodes().nodes.find(n => n.kind === 'command')
+      expect(running).toMatchObject({ outcome: null })
+      adapter.append(ev.commandDone(7, 'cmd-4'))
+      const settled = adapter.nodes().nodes.find(n => n.kind === 'command')
+      expect(settled).toMatchObject({ seq: 6, outcome: { kind: 'success' } })
+      // Settlement replaced the node object rather than mutating the published one.
+      expect(settled).not.toBe(running)
+    })
+
+    it('tails command nodes whose seq is past every surface node', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([ev.user(0, '问'), ev.commandRun(1, 'cmd-tail', 'plan')], 0)
+      expect(adapter.nodes().nodes.map(n => n.kind)).toEqual(['user', 'command'])
+    })
+
+    it('command nodes survive the degraded linear-scan branch', () => {
+      const adapter = new FoldAdapter()
+      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
+      try {
+        adapter.reset([
+          ev.commandRun(0, 'cmd-5', 'plan'),
+          ev.commandDone(1, 'cmd-5'),
+          at(2, { type: 'assistant/message', surfaceOp: 'bogus-op', data: {
+            turn: 0,
+            step: 0,
+            message: createMessage({
+              role: 'assistant',
+              content: [{ type: 'text', text: '坏 op' }],
+              source: { kind: 'model', provider: 'x', model: 'y' },
+            }),
+          } }),
+        ], 0)
+        const { nodes, degraded } = adapter.nodes()
+        expect(degraded).toBe(true)
+        expect(nodes.some(n => n.kind === 'command')).toBe(true)
+      } finally {
+        errorSpy.mockRestore()
+      }
+    })
+  })
 })