Merge origin/master into web-permission-sandbox

39 conflicts resolved per the reattachment plan (missions worktree-projbiz
0728-1859): baseline wins for deleted packages (host/runtime, old ui/acp,
ui-sidebar Rows/tree) and retired specs; unions for wire-layer exports and
client summary fields; the approval takeover, waitingApprovals tracking, and
PendingApproval domain face carry over onto the master structure. The two
new host specs follow the runtime->apiproxy rename. Dead PR-side wiring
(ConversationInjected permissions/setPermission spread, InputBar controls
prop, boot.ts sandbox composition) resolves to master and its replacement
lands in follow-up commits.

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

@@ -1,21 +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), the Session object layer (exported as a type; instances are owned and handed out by SessionsService — the manager/paging internals stay package-internal, tests reach them via src), 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 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 (`cell()`/`binding()`/`scope()`) is pure addressing, render-safe. The staged state can widen to a multi-pane list when concurrent panes land.
+- **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).

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

@@ -32,10 +32,13 @@
   "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-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",
     "zustand": "~4.4.7"

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

@@ -161,11 +161,7 @@ function deepFreeze(value: unknown): void {
   }
 }
 
-// ---- defineStore shell (slot terminal design §4) ----
-// The type authority is ui-slots' store family (create(scopeKey?) and
-// clearPersisted() included); this module houses only the engine-backed
-// implementation. The one engine-side widening left: instances expose the
-// raw engine store for framework/test surfaces.
+// 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> {

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

@@ -1,43 +1,45 @@
-/**
- * Browser half: the whole runtime contract surface (api-contracts v3 §4) —
- * SlotsService (declaration ledger + renderer seam + store axis, built-in
- * 'root'), SessionsService (list store + current selection + scope tree +
- * object layer), and the cordis Context/Events merges. apply mounts
- * ctx.slots + ctx.sessions and wires the connection stream loop into the
- * object layer. A static-arrival entry: the web shell bundles this module
- * and mounts it through the host graph (module loading lives in
- * @deepseek-ai/dsh-client-modules, entry governance in the vendored Loader).
- */
+/** Browser runtime services for slots, sessions, workspaces, and connection-stream delivery. */
 import type { Context } from 'cordis'
 import type { ConnectionHandle, SessionId } from '@deepseek-ai/dsh-client-connection/client'
-import type { SnapshotSelectorHook } from '@deepseek-ai/dsh-client-ui-slots'
+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'
-// RootOwnerProps rides the 'root' SlotMap row (both migrated here from
-// ui-layout: the framework slot is declared by the framework package).
 export type { RootOwnerProps } from './slots.ts'
-export { SessionsService, scopeOf } from './sessions/service.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 { SessionBinding, SessionListState, SessionSummary } from './sessions/service.ts'
-// The snapshot-store engine lives here since the store migration (the data
-// layer owns its substrate; web-react is React glue only). The './client'
-// main export is the single serving door — no store subpath.
+export type {
+  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, ContextMessageNode, ConversationNode, ConversationSnapshot,
-  RunningToolCall, SteeringMessageNode,
-  ToolResultNode, UnknownSurfaceNode, UserMessageNode,
+  AssistantBlock, AssistantMessageNode, CodeSubCall, CommandNode, ComposerPhase, ContextMessageNode, ConversationNode,
+  ConversationSnapshot, QueuedMessage, RunningToolCall,
+  SteeringMessageNode, TodoItem, ToolResultNode, UnknownSurfaceNode, UserMessageNode,
 } from './sessions/conversation.ts'
-// PendingWait is a value export: tests construct fixture waits directly.
 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 { PermissionOption, SessionId } from '@deepseek-ai/dsh-client-connection/client'
 
 /** The permission select material as the object layer serves it to UI plugins. */
@@ -48,16 +50,7 @@ export interface PermissionSelect {
   currentValue: string
 }
 
-// ---- 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
 
 /** The conversation-snapshot selector hook (ConvViewProps/ToolRowProps take this). */
@@ -77,15 +70,25 @@ declare module '@deepseek-ai/dsh-client-ui-slots' {
    * every session-scope slot component receives these from the framework.
    */
   interface SessionStandardProps {
-    /** Selector hook over this session's conversation snapshot. */
     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
   }
-  /** Global standard kit, real members: the session-list hook every slot component receives. */
+  /** 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 {
-    /** Selector hook over the session list snapshot (`current` included — the arbitrated selection seat). */
     useSessions: SnapshotSelectorHook<SessionListState>
+    /** Selector hook over real Workspaces and their independent baseline lifecycle. */
+    useWorkspaces: SnapshotSelectorHook<import('./workspaces/service.ts').WorkspaceListState>
   }
 }
 
@@ -97,28 +100,57 @@ 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
+    workspaces: import('./workspaces/service.ts').WorkspacesService
   }
 }
 
 /** 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/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

@@ -3,10 +3,16 @@
 // 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 { RpcError, 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). */
 export type AssistantBlock =
@@ -82,7 +88,6 @@ export interface ContextMessageNode {
   time: number
   content: readonly ContentBlock[]
   source: unknown
-  meta?: unknown
 }
 
 /** A tool result paired (when in-window) with its call head. */
@@ -116,6 +121,31 @@ export interface UnknownSurfaceNode {
   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
@@ -123,8 +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
@@ -139,6 +185,12 @@ export interface RunningToolCall {
 }
 
 
+/** 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 {
   turn: number
@@ -149,6 +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'
@@ -164,8 +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
@@ -173,5 +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
 }

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). */
@@ -24,10 +25,10 @@ export interface CallIndexEntry {
   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
 }
@@ -40,6 +41,14 @@ function materializeNode(
 ): ConversationNode {
   switch (event.type) {
     case 'user/message':
+      // 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,
@@ -48,34 +57,30 @@ function materializeNode(
       return {
         kind: 'assistant', seq: event.seq, time: event.time,
         turn: event.data.turn, step: event.data.step,
-        blocks: toAssistantBlocks(event.data.content), usage: event.data.usage,
+        blocks: toAssistantBlocks(event.data.message.content), usage: event.data.usage,
       }
     case 'steering/message':
       return {
         kind: 'steering', seq: event.seq, time: event.time, turn: event.data.turn,
-        content: event.data.content, source: event.data.source,
-      }
-    case 'context/message':
-      return {
-        kind: 'context', seq: event.seq, time: event.time,
-        content: event.data.content, source: event.data.source,
-        meta: event.data.meta,
+        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, time: event.time,
-        callId: String(event.data.callId),
+        callId,
         call: call ? { name: call.name, argsRaw: call.argsRaw } : null,
         callTime: call?.time ?? null,
-        content: event.data.content, isError: event.data.isError,
+        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:
@@ -97,6 +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. */
@@ -126,10 +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)
+      }
     }
   }
 
@@ -143,6 +161,7 @@ export class FoldAdapter {
     this.rev++
     this.padded.push(event)
     this.indexCall(event, view)
+    this.indexCommand(event)
   }
 
   /**
@@ -178,7 +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
   }
@@ -193,6 +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)

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

@@ -1,6 +1,6 @@
 // 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'
 
@@ -15,6 +15,8 @@ export interface SessionListEntry {
   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
   /** An approval question is pending on this session (mux-frame derived; the sidebar's amber dot). */
@@ -24,8 +26,9 @@ 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.
  * @param waitingApproval - sessions with a pending approval question (manager-owned live fact; absent = false).
  * @returns display rows in render order.
@@ -46,9 +49,6 @@ export function flattenLineage(summaries: readonly TitledSessionSummary[], waiti
     }
   }
 
-  const byUpdatedDesc = (a: TitledSessionSummary, b: TitledSessionSummary): number => b.updatedAt - a.updatedAt
-  roots.sort(byUpdatedDesc)
-
   const out: SessionListEntry[] = []
   const visited = new Set<SessionId>()
   const walk = (s: TitledSessionSummary, depth: number): void => {
@@ -60,7 +60,6 @@ export function flattenLineage(summaries: readonly TitledSessionSummary[], waiti
     out.push({ ...s, waitingApproval: waitingApproval?.has(s.sessionId) ?? false, 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

@@ -2,31 +2,52 @@
 // 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 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
 
-/** Latest title control snapshot retained independently of list/instance arrival. */
-interface SessionTitleSnapshot {
-  title: string
-  eventSeq: number
-  updatedAt: number
-}
 
 /** Instance cluster + frame entry + the session list (see the web client architecture RFC). */
 export class SessionManager {
@@ -41,11 +62,21 @@ export class SessionManager {
    *  because the sidebar must light up for sessions never instantiated. Cleared per connection
    *  generation — the reopen replay re-adds still-pending questions — and on session-removed. */
   private readonly waitingApprovals = new Map<SessionId, Set<string>>()
-  private readonly titleSnapshots = new Map<SessionId, SessionTitleSnapshot>()
+  /** 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
@@ -57,12 +88,50 @@ 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).
@@ -72,21 +141,53 @@ 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). */
@@ -94,15 +195,28 @@ 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
@@ -113,6 +227,7 @@ 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()
       }
@@ -122,19 +237,38 @@ 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) {
@@ -142,6 +276,23 @@ 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) ----
 
   /**
@@ -173,22 +324,32 @@ 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/title') {
-      const current = this.titleSnapshots.get(frame.sessionId)
-      if (current !== undefined && current.eventSeq >= frame.eventSeq) return
-      this.titleSnapshots.set(frame.sessionId, {
-        title: frame.title,
-        eventSeq: frame.eventSeq,
-        updatedAt: frame.updatedAt,
-      })
+    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') {
-      const current = this.titleSnapshots.get(frame.sessionId)
-      if (current !== undefined && current.eventSeq > frame.lastSeq) {
-        this.titleSnapshots.delete(frame.sessionId)
-        this.notifier.markDirty()
+      // 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)
+        }
       }
     }
     // List-level waiting-approval bit (the sidebar amber dot): tracked here for
@@ -209,13 +370,15 @@ export class SessionManager {
     }
     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)
@@ -237,32 +400,25 @@ 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.waitingApprovals.delete(frame.sessionId) // a removed session cannot wait on anyone
-        this.titleSnapshots.delete(frame.sessionId)
-        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': {
@@ -274,7 +430,7 @@ 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 {
     // Approvals resolved while disconnected send no frame: drop the bits and
     // let the mux-open replay re-add every still-pending question.
@@ -288,16 +444,19 @@ export class SessionManager {
 
   private buildListSnapshot(): SessionListSnapshot {
     const merged: TitledSessionSummary[] = this.summaries.map((summary) => {
-      const title = this.titleSnapshots.get(summary.sessionId)
-      return title === undefined
-        ? summary
-        : { ...summary, title: title.title, updatedAt: Math.max(summary.updatedAt, title.updatedAt) }
+      // 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, new Set(this.waitingApprovals.keys()))
     const items = fresh.map((entry) => {
       const prev = this.entryCache.get(entry.sessionId)
       if (
         prev !== undefined && prev.updatedAt === entry.updatedAt && prev.running === entry.running
+        && prev.blank === entry.blank
         && prev.parentSessionId === entry.parentSessionId && prev.cwd === entry.cwd
         && prev.title === entry.title && prev.depth === entry.depth
         && prev.waitingApproval === entry.waitingApproval
@@ -310,6 +469,57 @@ 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/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

@@ -2,8 +2,9 @@
  * SessionsService: root sessions service — list snapshot store (manager
  * projection; carries `current`, the persisted selection every
  * session-scoped surface keys off — migrated here from ui-layout per the
- * slot-parity design), session scope tree (mintScope pattern: no-op plugin
- * Fiber + ctx.extend scope tag), stable SessionBinding cache, ancestry walk.
+ * 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 stage-driven: a scope is minted lazily on first
  * resolution (pure — resolution has no side effects and is render-safe);
@@ -15,11 +16,15 @@
  * 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 { SessionCell } from '@deepseek-ai/dsh-client-ui-slots'
+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. */
@@ -34,6 +39,13 @@ export interface SessionSummary {
   running: boolean
   /** An approval question is pending on this session (sidebar amber-dot state). */
   waitingApproval: 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
 }
 
@@ -42,7 +54,29 @@ export interface SessionSummary {
  * 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 }
+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 {
@@ -51,21 +85,25 @@ 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: durable title, project directory basename, then
  * the raw id.
@@ -73,8 +111,8 @@ function sessionScope(): void {}
 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
 }
@@ -83,16 +121,45 @@ interface ScopeRecord {
   fiber: Fiber
   ctx: Context
   binding: SessionBinding
-  /** Render-layer standard kit (identity-stable per scope; the renderer's per-cell caches key off it). */
-  cell: SessionCell
+  /** Render-layer standard-props bundle (identity-stable per scope; the renderer's per-info caches key off it). */
+  provideInfo: SessionProvideInfo
+}
+
+/** 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) — 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
@@ -105,6 +172,14 @@ export class SessionsService {
   private readonly selection: SnapshotStore<{ sessionId?: SessionId }>
 
   private readonly scopes = new Map<SessionId, ScopeRecord>()
+  /** 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
@@ -119,12 +194,14 @@ export class SessionsService {
    * @param ctx - client root context (scope fibers mount under it).
    * @param api - wire client shared with every Session.
    */
-  constructor(private readonly rootCtx: Context, private readonly api: IApiClient) {
-    this.manager = new SessionManager(api)
+  constructor(private readonly rootCtx: Context, api: IApiClient) {
     this.selection = createSnapshotStore<{ sessionId?: SessionId }>(
       {},
       { persist: { name: 'dsh.sessions.current' } })
-    this.list = createSnapshotStore<SessionListState>({ ids: [], byId: {}, current: undefined })
+    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() })
@@ -134,69 +211,211 @@ export class SessionsService {
     // 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.
-    this.list.subscribe(() => { this.followCurrent() })
+    // 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)
   }
 
+  /**
+   * 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).
+   */
+  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 {
-    if (this.list.getSnapshot().byId[id] === undefined) {
-      throw new Error(`sessions.open: unknown session ${id}`)
-    }
-    this.selection.update((draft) => { draft.sessionId = id })
-    this.list.update((draft) => { draft.current = id })
+    this.manager.select(id)
   }
 
   /**
    * Clear the current selection so the layout shows the no-session empty
-   * state. Wipes the persisted selection too — a reload stays on empty until
-   * the user opens or starts a session. Staging holds the previous occupant
-   * across the blank (same masked-gap rule as a transient list miss).
+   * 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.selection.set({})
-    this.list.update((draft) => { draft.current = undefined })
+    this.manager.clearSelection()
   }
 
   /**
-   * Create a session on the host.
-   * @param opts - creation options (project directory).
-   * @returns the new session id.
+   * Refresh the real Session baseline, reusing an in-flight pull.
+   * @returns completion of the current or newly started baseline pull.
    */
-  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}`)
+  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
   }
 
   /**
-   * Create a workspace folder under the host process cwd and a session in it.
-   * Name is a single path segment (no separators); the host mkdir runs inside
-   * session.create. Caller opens the returned id when it wants the session staged.
-   * @param name - workspace folder basename.
-   * @returns the new session id.
-   */
-  async createWorkspace(name: string): Promise<SessionId> {
-    const trimmed = name.trim()
-    if (trimmed === '') throw new Error('sessions.createWorkspace: name is required')
-    if (/[/\\]/.test(trimmed)) {
-      throw new Error('sessions.createWorkspace: name must not contain path separators')
-    }
-    const { result } = await this.api.host.describe({})
-    if (!result.ok) {
-      throw new Error(`host.describe failed: ${result.error.code}: ${result.error.message}`)
-    }
-    const hostCwd = result.value.cwd.replace(/[/\\]+$/, '')
-    return this.create({ cwd: `${hostCwd}/${trimmed}` })
-  }
-
-  /**
-   * 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 {
@@ -204,7 +423,7 @@ export class SessionsService {
   }
 
   /**
-   * Read the session scope tag off a context. Service-method seam: fetch
+   * 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.
@@ -212,7 +431,22 @@ export class SessionsService {
    * @returns the session id, or undefined on root contexts.
    */
   scopeOf(ctx: Context): SessionId | undefined {
-    return scopeOf(ctx)
+    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
   }
 
   /**
@@ -226,16 +460,22 @@ export class SessionsService {
   }
 
   /**
-   * Resolve the render-layer session cell (SessionProvider's feed through
-   * the renderer host; ctx never enters the render layer). Pure resolution —
-   * render-safe: SessionProvider calls this during render, so no staging, no
-   * window side effects (StrictMode double-invokes and concurrent discarded
-   * passes must stay free).
-   * @param id - session id.
-   * @returns cell, or undefined for a session neither listed nor already scoped.
+   * 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).
    */
-  cell(id: string): SessionCell | undefined {
-    return this.resolve(id as SessionId)?.cell
+  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
   }
 
   /**
@@ -246,11 +486,12 @@ export class SessionsService {
    * failed one retries the next time current is touched).
    */
   private followCurrent(): void {
-    const current = this.list.getSnapshot().current
+    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 || current === this.watched) return
+    if (current === undefined || snapshot.byId[current] === undefined || current === this.watched) return
     this.watched = current
     this.sweepDeferred()
     const record = this.resolve(current)
@@ -280,30 +521,42 @@ 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, ctx },
-      // Bare source form (store migration): the Session object IS the
-      // observable; the React side binds the useSession hook per cell.
-      cell: { sessionId: id, session },
+      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) {
@@ -313,24 +566,30 @@ export class SessionsService {
         displayTitle: displayTitleOf(entry.title, entry.cwd, entry.sessionId),
         running: entry.running,
         waitingApproval: entry.waitingApproval,
+        blank: entry.blank,
         updatedAt: entry.updatedAt,
         ...(entry.title !== undefined ? { title: entry.title } : {}),
         ...(entry.cwd !== undefined ? { cwd: entry.cwd } : {}),
         ...(entry.parentSessionId !== undefined ? { parentId: entry.parentSessionId } : {}),
       }
     }
-    // current = the persisted selection, masked while its session is absent
-    // (falls to the empty state; resurfaces if the session returns).
-    const selected = this.selection.getSnapshot().sessionId
-    const current = selected !== undefined && byId[selected] !== undefined ? selected : undefined
-    this.list.set({ ids, byId, current })
+    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 off stage; the staged one defers until the stage 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
@@ -341,12 +600,22 @@ export class SessionsService {
     }
   }
 
-  /** Dispose a scope fiber and its session-keyed slot-store instances together (single lifecycle axis). */
+  /**
+   * 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). */
@@ -356,8 +625,8 @@ export class SessionsService {
        * 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
       }

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

@@ -1,8 +1,6 @@
-// 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 {
@@ -14,22 +12,62 @@ import type {
 import { transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
 import type { ObservableSnapshot } from '../contract/store.ts'
 import type {
-  ConversationNode, ConversationSnapshot, OpenState, PromptError, RunningToolCall,
+  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
 
+/** 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
+}
+
 /**
- * Per-session state owner: event window + fold + partial, snapshot out via
- * subscribe/getSnapshot (see the web client architecture RFC). Bare source
- * only (store migration): the React machinery binds the per-cell useSession
- * hook at its own seam — no selector hook member lives on the data layer.
+ * 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) ----
@@ -54,8 +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.
@@ -63,28 +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
-  /** 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
   }
@@ -207,6 +327,11 @@ 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
@@ -255,12 +380,36 @@ 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': {
         const { type: _type, sessionId: _sid, ...payload } = frame
@@ -297,11 +446,40 @@ 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
@@ -317,8 +495,7 @@ 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 ----
@@ -350,13 +527,13 @@ 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'
     } catch (error) {
@@ -373,14 +550,18 @@ 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)
@@ -429,7 +610,7 @@ 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)
@@ -438,9 +619,89 @@ 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
@@ -466,7 +727,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
         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': {
@@ -520,6 +781,8 @@ 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. */
@@ -552,21 +815,50 @@ 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,
     }
   }
 }
+
+/**
+ * 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

@@ -235,19 +235,16 @@ export class SlotsService extends Service {
     }
   }
 
-  /** Build (once) the host face the installed renderer reads; sessions resolve lazily at first render. */
+  /** 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")
     }
-    // Identity-stable view: current rides the list snapshot (arbitrated), but
-    // the provider consumes it as its own observable; one cached object keeps
-    // the renderer's per-source hook cache stable.
-    const current = {
-      getSnapshot: () => sessions.list.getSnapshot().current as string | undefined,
-      subscribe: (fn: () => void) => sessions.list.subscribe(fn),
+    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),
@@ -259,9 +256,9 @@ export class SlotsService extends Service {
         entry.store === undefined ? undefined : this.resolveStore(entry.store as unknown as EngineStoreHandle, scopeKey),
       sessions: {
         list: sessions.list,
-        current,
-        cell: id => sessions.cell(id),
+        provideInfo: sessions.currentProvideInfo,
       },
+      workspaces: { list: workspaces.list },
     }
     return this._host
   }
@@ -270,13 +267,13 @@ export class SlotsService extends Service {
   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 === 'session' ? sessionId : ROOT_INSTANCE_KEY
-    if (key === undefined) throw new Error('session-scoped store resolution requires a session id')
+    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 === 'session' ? handle.create(key) : handle.create()
+      instance = record.scope === 'root' ? handle.create() : handle.create(key)
       record.instances.set(key, instance)
     }
     return instance

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
@@ -33,29 +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/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 {
-  ClientResponse, HostFrame, IApiClient, MuxFrame, RpcError, RpcReceipt, 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
@@ -46,10 +62,23 @@ 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 }))
   onPermissions: (payload: unknown) =>
@@ -61,6 +90,10 @@ export class FakeApiClient implements IApiClient {
 
   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>[] = []
@@ -73,6 +106,9 @@ 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)),
     permissions: (payload: unknown) => this.record('session.permissions', payload, this.onPermissions(payload)),
@@ -81,6 +117,49 @@ export class FakeApiClient implements IApiClient {
 
   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)),
   }
 
   /** When true, streams never fire onOpen (misbehaving-carrier material for the handshake timeout guard). */

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()
+      }
+    })
+  })
 })

packages/client/runtime/tests/lineage.spec.ts

@@ -8,12 +8,12 @@ import type { SessionId, SessionSummary } from '@deepseek-ai/dsh-client-connecti
 import { flattenLineage } from '../src/client/sessions/lineage.ts'
 
 const s = (id: string, updatedAt: number, parent?: string): SessionSummary => ({
-  sessionId: id as SessionId, updatedAt, running: false,
+  sessionId: id as SessionId, updatedAt, running: false, blank: false,
   ...(parent !== undefined ? { parentSessionId: parent as SessionId } : {}),
 })
 
 describe('flattenLineage', () => {
-  it('sorts roots by updatedAt desc and expands children DFS with depth, children sorted too', () => {
+  it('keeps established root and sibling order while expanding children DFS with depth', () => {
     const out = flattenLineage([
       s('old-root', 10),
       s('new-root', 30),
@@ -22,7 +22,7 @@ describe('flattenLineage', () => {
       s('grandkid', 5, 'kid-new'),
     ])
     expect(out.map(e => [e.sessionId, e.depth])).toEqual([
-      ['new-root', 0], ['kid-new', 1], ['grandkid', 2], ['kid-old', 1], ['old-root', 0],
+      ['old-root', 0], ['new-root', 0], ['kid-old', 1], ['kid-new', 1], ['grandkid', 2],
     ])
   })
 

packages/client/runtime/tests/manager.spec.ts

@@ -12,8 +12,10 @@ import { entries, plainTurn } from './event-script.ts'
 const S1 = 'fk-m1' as SessionId
 const S2 = 'fk-m2' as SessionId
 
-function summary(sessionId: SessionId, over: Partial<{ updatedAt: number; running: boolean; parentSessionId: SessionId }> = {}) {
-  return { sessionId, updatedAt: 100, running: false, ...over }
+type SummaryOver = Partial<{ updatedAt: number; running: boolean; blank: boolean; parentSessionId: SessionId }>
+
+function summary(sessionId: SessionId, over: SummaryOver = {}) {
+  return { sessionId, updatedAt: 100, running: false, blank: false, ...over }
 }
 
 describe('instances', () => {
@@ -57,7 +59,7 @@ describe('instances', () => {
 })
 
 describe('list lifecycle', () => {
-  it('single-flights refreshList and lands items sorted through lineage flattening', async () => {
+  it('single-flights refreshList and preserves the Host baseline order', async () => {
     const api = new FakeApiClient()
     const gate = deferred<Awaited<ReturnType<FakeApiClient['onList']>>>()
     api.onList = () => gate.promise
@@ -65,12 +67,33 @@ describe('list lifecycle', () => {
     const first = manager.refreshList()
     const second = manager.refreshList()
     expect(manager.getListSnapshot().state).toBe('loading')
-    gate.resolve(ok({ items: [summary(S1), summary(S2, { updatedAt: 200 })] as never[] }))
+    gate.resolve(ok({ items: [summary(S2, { updatedAt: 200 }), summary(S1)] as never[] }))
     await Promise.all([first, second])
     expect(api.callsOf('session.list')).toHaveLength(1)
     const snapshot = manager.getListSnapshot()
     expect(snapshot.state).toBe('idle')
-    expect(snapshot.items.map(i => i.sessionId)).toEqual([S2, S1]) // updatedAt desc
+    expect(snapshot.items.map(i => i.sessionId)).toEqual([S2, S1])
+  })
+
+  it('replays incremental frames over hydration and never batch-reorders established ids', async () => {
+    const api = new FakeApiClient()
+    const first = deferred<Awaited<ReturnType<FakeApiClient['onList']>>>()
+    api.onList = () => first.promise
+    const manager = new SessionManager(api)
+    const hydration = manager.refreshList()
+    manager.handleHostEnvelope({
+      rpcId: 'during-first' as never,
+      payload: { type: 'host/session-added', blank: true, sessionId: S2 },
+    })
+    first.resolve(ok({ items: [summary(S1)] as never[] }))
+    await hydration
+    expect(manager.getListSnapshot().items.map(item => item.sessionId)).toEqual([S2, S1])
+
+    api.onList = () => Promise.resolve(ok({
+      items: [summary(S1, { updatedAt: 900 }), summary(S2, { updatedAt: 800 })] as never[],
+    }))
+    await manager.refreshList()
+    expect(manager.getListSnapshot().items.map(item => item.sessionId)).toEqual([S2, S1])
   })
 
   it('keeps the error in the list snapshot on failure', async () => {
@@ -79,6 +102,26 @@ describe('list lifecycle', () => {
     const manager = new SessionManager(api)
     await manager.refreshList()
     expect(manager.getListSnapshot()).toMatchObject({ state: 'error', error: { code: 'internal' } })
+    // A failed pull does not step the arrival phase: still pending.
+    expect(manager.getListSnapshot().phase).toBe('pending')
+  })
+
+  it('phase steps pending → ready on the first successful pull and never returns', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    expect(manager.getListSnapshot().phase).toBe('pending')
+    await manager.refreshList()
+    expect(manager.getListSnapshot().phase).toBe('ready')
+    // Sticky across later failures: the pull-activity axis reports the error,
+    // the arrival phase holds.
+    api.onList = () => Promise.resolve(err({ code: 'internal', message: 'down', details: {} }))
+    await manager.refreshList()
+    expect(manager.getListSnapshot()).toMatchObject({ state: 'error', phase: 'ready' })
+    // And across an empty re-pull (empty-with-ready = truly no sessions).
+    api.onList = () => Promise.resolve(ok({ items: [] as never[] }))
+    await manager.refreshList()
+    expect(manager.getListSnapshot()).toMatchObject({ state: 'idle', phase: 'ready' })
+    expect(manager.getListSnapshot().items).toEqual([])
   })
 
   it('merges create into the list immediately without waiting for a refresh', async () => {
@@ -90,21 +133,18 @@ describe('list lifecycle', () => {
     expect(manager.getListSnapshot().items.map(i => i.sessionId)).toEqual([S2])
   })
 
-  it('retains monotonic title snapshots before list arrival, merges recency, and clears them on removal', async () => {
+  it('retains title projections before list arrival, keeps last-wins by seq, and clears them on removal', async () => {
     const api = new FakeApiClient()
     const manager = new SessionManager(api)
-    manager.handleMuxEnvelope({
-      rpcId: 'title-new' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Newest', eventSeq: 4, updatedAt: 300 },
-    })
-    manager.handleMuxEnvelope({
-      rpcId: 'title-stale' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Stale', eventSeq: 3, updatedAt: 900 },
-    })
-    manager.handleMuxEnvelope({
-      rpcId: 'title-equal' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Equal', eventSeq: 4, updatedAt: 901 },
-    })
+    const titleFrame = (rpcId: string, title: string, seq: number) => {
+      manager.handleMuxEnvelope({
+        rpcId: rpcId as never,
+        payload: { type: 'session/projection', sessionId: S1, key: 'title', value: title, seq } as never,
+      })
+    }
+    titleFrame('title-new', 'Newest', 4)
+    titleFrame('title-stale', 'Stale', 3)
+    titleFrame('title-equal', 'Equal', 4)
     api.onList = () => Promise.resolve(ok({
       items: [summary(S1), summary(S2, { updatedAt: 200 })] as never[],
     }))
@@ -112,42 +152,35 @@ describe('list lifecycle', () => {
 
     const titled = manager.getListSnapshot()
     expect(titled.items.map(item => item.sessionId)).toEqual([S1, S2])
-    expect(titled.items[0]).toMatchObject({ title: 'Newest', updatedAt: 300 })
+    expect(titled.items[0]?.title).toBe('Newest')
     expect(titled.items[1]?.title).toBeUndefined()
 
     manager.handleHostEnvelope({ rpcId: 'removed' as never, payload: { type: 'host/session-removed', sessionId: S1 } })
-    manager.handleHostEnvelope({ rpcId: 'readded' as never, payload: { type: 'host/session-added', sessionId: S1 } })
+    manager.handleHostEnvelope({ rpcId: 'readded' as never, payload: { type: 'host/session-added', blank: true, sessionId: S1 } })
     expect(manager.getListSnapshot().items.find(item => item.sessionId === S1)?.title).toBeUndefined()
   })
 
-  it('drops a retained title beyond the subscription baseline before accepting its durable replay', async () => {
+  it('drops a projection row beyond the subscription baseline before accepting its durable replay', async () => {
     const api = new FakeApiClient()
     api.onList = () => Promise.resolve(ok({ items: [summary(S1)] as never[] }))
     const manager = new SessionManager(api)
     await manager.refreshList()
-    manager.handleMuxEnvelope({
-      rpcId: 'title-unflushed' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Unflushed', eventSeq: 4, updatedAt: 400 },
-    })
+    const frame = (rpcId: string, payload: object) => {
+      manager.handleMuxEnvelope({ rpcId: rpcId as never, payload: payload as never })
+    }
+    frame('title-unflushed', { type: 'session/projection', sessionId: S1, key: 'title', value: 'Unflushed', seq: 4 })
 
-    manager.handleMuxEnvelope({
-      rpcId: 'subscribed-recovered' as never,
-      payload: { type: 'session/subscribed', sessionId: S1, lastSeq: 2 },
-    })
+    // The durable baseline says the host only knows up to seq 2: the phantom
+    // row rode lost state and must drop, or last-wins pins it forever.
+    frame('subscribed-recovered', { type: 'session/subscribed', sessionId: S1, lastSeq: 2 })
     expect(manager.getListSnapshot().items[0]?.title).toBeUndefined()
-    expect(manager.getListSnapshot().items[0]?.updatedAt).toBe(100)
 
-    manager.handleMuxEnvelope({
-      rpcId: 'title-durable' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Durable', eventSeq: 2, updatedAt: 200 },
-    })
-    expect(manager.getListSnapshot().items[0]).toMatchObject({ title: 'Durable', updatedAt: 200 })
+    frame('title-durable', { type: 'session/projection', sessionId: S1, key: 'title', value: 'Durable', seq: 2 })
+    expect(manager.getListSnapshot().items[0]?.title).toBe('Durable')
 
-    manager.handleMuxEnvelope({
-      rpcId: 'subscribed-current' as never,
-      payload: { type: 'session/subscribed', sessionId: S1, lastSeq: 2 },
-    })
-    expect(manager.getListSnapshot().items[0]).toMatchObject({ title: 'Durable', updatedAt: 200 })
+    // A baseline at or past the row's seq keeps it (nothing phantom to drop).
+    frame('subscribed-current', { type: 'session/subscribed', sessionId: S1, lastSeq: 2 })
+    expect(manager.getListSnapshot().items[0]?.title).toBe('Durable')
   })
 })
 
@@ -155,8 +188,8 @@ describe('host frame routing', () => {
   it('adds/removes/flips sessions from host frames and keeps removed instances resident', async () => {
     const api = new FakeApiClient()
     const manager = new SessionManager(api)
-    manager.handleHostEnvelope({ rpcId: 'h1' as never, payload: { type: 'host/session-added', sessionId: S1 } })
-    manager.handleHostEnvelope({ rpcId: 'h2' as never, payload: { type: 'host/session-added', sessionId: S1 } }) // dup: ignored
+    manager.handleHostEnvelope({ rpcId: 'h1' as never, payload: { type: 'host/session-added', blank: true, sessionId: S1 } })
+    manager.handleHostEnvelope({ rpcId: 'h2' as never, payload: { type: 'host/session-added', blank: true, sessionId: S1 } }) // dup: ignored
     expect(manager.getListSnapshot().items).toHaveLength(1)
 
     const session = manager.get(S1)
@@ -192,14 +225,14 @@ describe('remaining branches', () => {
     expect(session.getSnapshot().running).toBe(true)
   })
 
-  it('create passes cwd through, folds transport throws, and skips the merge when already listed', async () => {
+  it('create passes cwd and a preallocated id, folds transport throws, and deduplicates the echo', async () => {
     const api = new FakeApiClient()
     api.onCreate = () => Promise.resolve(ok({ sessionId: S1 }))
     const manager = new SessionManager(api)
-    await manager.create('/tmp/w')
-    expect(api.callsOf('session.create')).toEqual([{ cwd: '/tmp/w' }])
+    await manager.create({ cwd: '/tmp/w', sessionId: S1 })
+    expect(api.callsOf('session.create')).toEqual([{ cwd: '/tmp/w', sessionId: S1 }])
     expect(manager.getListSnapshot().items[0]).toMatchObject({ sessionId: S1, cwd: '/tmp/w' })
-    await manager.create('/tmp/w') // same id returned: no duplicate row
+    await manager.create({ cwd: '/tmp/w' }) // same id returned: no duplicate row
     expect(manager.getListSnapshot().items).toHaveLength(1)
     api.onCreate = () => Promise.reject(new Error('create wire down'))
     expect(await manager.create()).toMatchObject({ ok: false, error: { code: 'internal' } })
@@ -208,6 +241,42 @@ describe('remaining branches', () => {
     expect(await manager.create()).toMatchObject({ ok: false })
   })
 
+  it('publishes a real Ungrouped summary from workspace-attach-failed', async () => {
+    const api = new FakeApiClient()
+    api.onCreate = () => Promise.resolve(err({
+      code: 'workspace-attach-failed',
+      message: 'published but unattached',
+      details: { sessionId: S1, workspaceId: 'w1' },
+    } as never))
+    const manager = new SessionManager(api)
+    const result = await manager.create({ workspaceId: 'w1' as never, sessionId: S1 })
+    expect(result).toMatchObject({ ok: false, error: { code: 'workspace-attach-failed' } })
+    expect(manager.getListSnapshot().items).toEqual([expect.objectContaining({ sessionId: S1 })])
+    expect(manager.getListSnapshot().items[0]).not.toHaveProperty('cwd')
+  })
+
+  it('reconciles a preallocated id after an ordinary transport failure', async () => {
+    const api = new FakeApiClient()
+    api.onCreate = () => Promise.reject(new Error('response lost'))
+    const manager = new SessionManager(api)
+    const failed = await manager.create({ workspaceId: 'w1' as never, sessionId: S1 })
+    expect(failed).toMatchObject({ ok: false, error: { message: 'response lost' } })
+    expect(manager.getListSnapshot().items).toEqual([])
+
+    manager.handleHostEnvelope({
+      rpcId: 'published-later' as never,
+      payload: { type: 'host/session-added', blank: true, sessionId: S1, cwd: '/w/one' },
+    })
+    expect(manager.getListSnapshot().items).toEqual([
+      expect.objectContaining({ sessionId: S1, cwd: '/w/one' }),
+    ])
+    manager.handleHostEnvelope({
+      rpcId: 'duplicate-frame' as never,
+      payload: { type: 'host/session-added', blank: true, sessionId: S1, cwd: '/w/one' },
+    })
+    expect(manager.getListSnapshot().items).toHaveLength(1)
+  })
+
   it('subscribe notifies on list changes and stops after unsubscribe', async () => {
     const api = new FakeApiClient()
     const manager = new SessionManager(api)
@@ -218,7 +287,7 @@ describe('remaining branches', () => {
     expect(notified).toBeGreaterThan(0)
     const seen = notified
     unsubscribe()
-    manager.handleHostEnvelope({ rpcId: 'h' as never, payload: { type: 'host/session-added', sessionId: S1 } })
+    manager.handleHostEnvelope({ rpcId: 'h' as never, payload: { type: 'host/session-added', blank: true, sessionId: S1 } })
     await new Promise(resolve => setTimeout(resolve, 0))
     expect(notified).toBe(seen)
   })
@@ -257,8 +326,8 @@ describe('remaining branches', () => {
   it('carries parentSessionId from host/session-added into the lineage row', () => {
     const api = new FakeApiClient()
     const manager = new SessionManager(api)
-    manager.handleHostEnvelope({ rpcId: 'h1' as never, payload: { type: 'host/session-added', sessionId: S1 } })
-    manager.handleHostEnvelope({ rpcId: 'h2' as never, payload: { type: 'host/session-added', sessionId: S2, parentSessionId: S1 } })
+    manager.handleHostEnvelope({ rpcId: 'h1' as never, payload: { type: 'host/session-added', blank: true, sessionId: S1 } })
+    manager.handleHostEnvelope({ rpcId: 'h2' as never, payload: { type: 'host/session-added', blank: true, sessionId: S2, parentSessionId: S1 } })
     const items = manager.getListSnapshot().items
     expect(items.find(e => e.sessionId === S2)).toMatchObject({ parentSessionId: S1, depth: 1 })
   })
@@ -267,7 +336,11 @@ describe('remaining branches', () => {
 describe('connected generation', () => {
   it('refreshes the list and resyncs only opened instances', async () => {
     const api = new FakeApiClient()
-    api.onHistory = () => Promise.resolve(ok({ events: entries(plainTurn(0, 0, 'a', 'b')) as never[], hasMore: false }))
+    api.onHistory = () => Promise.resolve(ok({
+      events: entries(plainTurn(0, 0, 'a', 'b')) as never[],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'deepseek-chat' },
+    }))
     const manager = new SessionManager(api)
     const openedSession = manager.get(S1)
     await openedSession.open()

packages/client/runtime/tests/projection-store.spec.ts

@@ -0,0 +1,187 @@
+/**
+ * Projection value store (session-projection RFC, push model): the single
+ * higher-seq-wins rule on both paths (a stale baseline cannot overwrite a
+ * newer push frame; a replayed frame cannot regress), capability absence as
+ * undefined, generation truncation, and the Session/manager wiring (tail-page
+ * seeding, session/projection frame routing pre- and post-instantiation, the
+ * list rows' title projection).
+ */
+import { describe, expect, it } from 'vitest'
+import type { SessionId } from '@deepseek-ai/dsh-client-connection/client'
+import { ProjectionValueStore } from '../src/client/sessions/projection-store.ts'
+import { Session } from '../src/client/sessions/session.ts'
+import { SessionManager } from '../src/client/sessions/manager.ts'
+import { FakeApiClient, ok } from './fake-api.ts'
+import { entries, plainTurn } from './event-script.ts'
+
+// Test-domain keys merged into the projection map (the interface package's
+// pure-type outlet), the same way domain host plugins merge theirs.
+declare module '@deepseek-ai/dsh-session-projection/types' {
+  interface SessionProjectionMap {
+    'test/marks': { marks: string[] }
+  }
+}
+
+const SID = 'fk-s1' as SessionId
+
+describe('ProjectionValueStore semantics', () => {
+  it('reads undefined until a value lands (capability absence)', () => {
+    const store = new ProjectionValueStore()
+    expect(store.get('test/marks')).toBeUndefined()
+    expect(store.faceOf('test/marks').getSnapshot()).toBeUndefined()
+  })
+
+  it('applies frames last-wins by seq: replayed and stale frames drop', () => {
+    const store = new ProjectionValueStore()
+    store.apply('test/marks', { marks: ['a'] }, 5)
+    store.apply('test/marks', { marks: ['a', 'b'] }, 9)
+    expect(store.get('test/marks')).toEqual({ marks: ['a', 'b'] })
+    store.apply('test/marks', { marks: ['stale'] }, 5)
+    store.apply('test/marks', { marks: ['equal'] }, 9)
+    expect(store.get('test/marks')).toEqual({ marks: ['a', 'b'] })
+  })
+
+  it('a stale baseline can neither overwrite nor clear a newer frame; a fresh one reseeds and clears', () => {
+    const store = new ProjectionValueStore()
+    store.apply('test/marks', { marks: ['frame-20'] }, 20)
+    // Stale cut: carried key loses to the newer frame; omitted key survives.
+    store.seed({ asOfSeq: 10, values: { 'test/marks': { marks: ['baseline-10'] } } })
+    expect(store.get('test/marks')).toEqual({ marks: ['frame-20'] })
+    store.seed({ asOfSeq: 15, values: {} })
+    expect(store.get('test/marks')).toEqual({ marks: ['frame-20'] })
+    // Fresh cut: carried key reseeds…
+    store.seed({ asOfSeq: 30, values: { 'test/marks': { marks: ['baseline-30'] } } })
+    expect(store.get('test/marks')).toEqual({ marks: ['baseline-30'] })
+    // …and an omitting fresh cut clears (capability absent as of the cut).
+    store.seed({ asOfSeq: 40, values: {} })
+    expect(store.get('test/marks')).toBeUndefined()
+  })
+
+  it('truncate drops rows past the durable baseline and keeps the rest', () => {
+    const store = new ProjectionValueStore()
+    store.apply('test/marks', { marks: ['durable'] }, 5)
+    store.apply('other', 'phantom', 50)
+    store.truncate(10)
+    expect(store.get('test/marks')).toEqual({ marks: ['durable'] })
+    expect(store.get('other')).toBeUndefined()
+  })
+
+  it('notifies the key face on change (batched) and not on dropped applications', async () => {
+    const store = new ProjectionValueStore()
+    let keyTicks = 0
+    let anyTicks = 0
+    store.faceOf('test/marks').subscribe(() => { keyTicks += 1 })
+    store.subscribeAny(() => { anyTicks += 1 })
+    store.apply('test/marks', { marks: ['a'] }, 5)
+    await Promise.resolve()
+    expect(keyTicks).toBe(1)
+    expect(anyTicks).toBe(1)
+    store.apply('test/marks', { marks: ['replay'] }, 3)
+    await Promise.resolve()
+    expect(keyTicks).toBe(1)
+    expect(anyTicks).toBe(1)
+  })
+
+  it('faces are identity-stable per key (the React binding cache premise)', () => {
+    const store = new ProjectionValueStore()
+    expect(store.faceOf('test/marks')).toBe(store.faceOf('test/marks'))
+  })
+})
+
+describe('Session tail-page seeding', () => {
+  it('seeds the store from a history response carrying a projections block', async () => {
+    const api = new FakeApiClient()
+    const session = new Session(SID, api)
+    api.onHistory = () => Promise.resolve(ok({
+      events: entries(plainTurn(0, 0, '问', '答')) as never[], hasMore: false,
+      projections: { asOfSeq: 5, values: { 'test/marks': { marks: ['from-baseline'] } } },
+    } as never))
+    await session.open()
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['from-baseline'] })
+  })
+
+  it('a resync serving a stale block keeps the newer pushed value (seq rule end to end)', async () => {
+    const api = new FakeApiClient()
+    const session = new Session(SID, api)
+    api.onHistory = () => Promise.resolve(ok({
+      events: entries(plainTurn(0, 0, 'a', 'b')) as never[], hasMore: false,
+      projections: { asOfSeq: 5, values: { 'test/marks': { marks: ['baseline'] } } },
+    } as never))
+    await session.open()
+    session.projections.apply('test/marks', { marks: ['pushed-9'] }, 9)
+    await session.resync()
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['pushed-9'] })
+  })
+
+  it('treats a blockless response as no reset: pushed values survive', async () => {
+    const api = new FakeApiClient()
+    const session = new Session(SID, api)
+    api.onHistory = () => Promise.resolve(ok({ events: entries(plainTurn(0, 0, 'a', 'b')) as never[], hasMore: false }))
+    await session.open()
+    session.projections.apply('test/marks', { marks: ['pushed'] }, 9)
+    await session.resync()
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['pushed'] })
+  })
+})
+
+describe('manager frame routing', () => {
+  const sid = (s: string): SessionId => s as SessionId
+
+  it('lands session/projection frames before instantiation and the Session adopts the same store', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    manager.handleMuxEnvelope({
+      rpcId: 'p1' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'test/marks', value: { marks: ['early'] }, seq: 7 } as never,
+    })
+    const session = manager.get(sid('s1'))
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['early'] })
+    // Frames after instantiation land in the same store.
+    manager.handleMuxEnvelope({
+      rpcId: 'p2' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'test/marks', value: { marks: ['later'] }, seq: 9 } as never,
+    })
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['later'] })
+  })
+
+  it('projects the title key into list rows and truncates phantom rows on the subscribed baseline', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    api.onList = () => Promise.resolve(ok({
+      items: [{ sessionId: sid('s1'), updatedAt: 1, running: false, blank: false }],
+    }) as never)
+    await manager.refreshList()
+    manager.handleMuxEnvelope({
+      rpcId: 't1' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'title', value: 'Projected title', seq: 4 } as never,
+    })
+    await Promise.resolve()
+    expect(manager.getListSnapshot().items[0]?.title).toBe('Projected title')
+    // The durable baseline says the host only knows up to seq 2: the row rode
+    // lost state and must drop (the un-flushed title precedent).
+    manager.handleMuxEnvelope({
+      rpcId: 'sub' as never,
+      payload: { type: 'session/subscribed', sessionId: sid('s1'), lastSeq: 2 } as never,
+    })
+    await Promise.resolve()
+    expect(manager.getListSnapshot().items[0]?.title).toBeUndefined()
+  })
+
+  it('drops the projection store with the removed session', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    api.onList = () => Promise.resolve(ok({
+      items: [{ sessionId: sid('s1'), updatedAt: 1, running: false, blank: false }],
+    }) as never)
+    await manager.refreshList()
+    manager.handleMuxEnvelope({
+      rpcId: 't1' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'title', value: 'Doomed', seq: 4 } as never,
+    })
+    manager.handleHostEnvelope({
+      rpcId: 'rm' as never,
+      payload: { type: 'host/session-removed', sessionId: sid('s1') } as never,
+    })
+    expect(manager.get(sid('s1')).projections.get('title')).toBeUndefined()
+  })
+})

packages/client/runtime/tests/queue-store.spec.ts

@@ -0,0 +1,234 @@
+/**
+ * Queue mirror semantics (web input-triggers queue cut 1): session/queued
+ * intake, host-rule retirement (message turn/start claims oldest non-steering;
+ * steering/message drains by source), leave-running sweep, reconnect reset,
+ * pre-instantiation buffering, and snapshot reference stability.
+ */
+import { describe, expect, it } from 'vitest'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
+import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
+import type { MuxFrame, RpcId, SessionId } from '@deepseek-ai/dsh-client-connection/client'
+import { Session } from '../src/client/sessions/session.ts'
+import { SessionManager } from '../src/client/sessions/manager.ts'
+import { FakeApiClient } from './fake-api.ts'
+import { ev } from './event-script.ts'
+
+const SID = 'fk-q1' as SessionId
+const text = (t: string): ContentBlock[] => [{ type: 'text', text: t }]
+const rid = (id: string): RpcId => id as RpcId
+
+/** session/queued frame with the wire-sourced rpcId key (the host prompt path). */
+function queuedFrame(body: string, rpcId: string, steering = false): MuxFrame {
+  return {
+    type: 'session/queued',
+    sessionId: SID,
+    message: createUserMessage({
+      content: text(body),
+      source: { kind: 'user', rpcId: rid(rpcId) } as never,
+    }),
+    steering,
+  }
+}
+
+function makeSession(): Session {
+  return new Session(SID, new FakeApiClient())
+}
+
+describe('queue intake', () => {
+  it('lands a queued frame as a row keyed by the source rpcId with a flat preview', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('env-1'), queuedFrame('第一条  排队\n消息', 'p-1'))
+    const queue = session.getSnapshot().queue
+    expect(queue).toEqual([{ key: 'p-1', preview: '第一条 排队 消息' }])
+  })
+
+  it('falls back to the envelope rpcId when the source carries none, and tags non-text blocks', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('env-2'), {
+      type: 'session/queued',
+      sessionId: SID,
+      message: createUserMessage({
+        content: [{ type: 'text', text: 'hi' }, { type: 'image', data: 'x' } as never],
+        source: { kind: 'plugin', plugin: 'loop' },
+      }),
+      steering: false,
+    })
+    expect(session.getSnapshot().queue).toEqual([{ key: 'f:env-2', preview: 'hi [image]' }])
+  })
+
+  it('caps the preview at 200 code points with an ellipsis', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('env-3'), queuedFrame('长'.repeat(201), 'p-cap'))
+    const preview = session.getSnapshot().queue[0]?.preview ?? ''
+    expect(Array.from(preview)).toHaveLength(201) // 200 + …
+    expect(preview.endsWith('…')).toBe(true)
+  })
+
+  it('keeps the queue array reference stable across unrelated snapshot swaps', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('env-4'), queuedFrame('稳定', 'p-s'))
+    const before = session.getSnapshot().queue
+    session.handleAgentError('unrelated') // dirties the snapshot without touching the queue
+    expect(session.getSnapshot().queue).toBe(before)
+  })
+})
+
+describe('queue retirement (host queuedMirror rules)', () => {
+  it('a message-triggered turn/start claims the oldest non-steering row', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('e1'), queuedFrame('先', 'p-1'))
+    session.handleMuxEnvelope(rid('e2'), queuedFrame('后', 'p-2'))
+    session.handleMuxEnvelope(rid('e3'), { type: 'session/event', sessionId: SID, event: ev.turnStart(0, 0) })
+    expect(session.getSnapshot().queue.map(r => r.key)).toEqual(['p-2'])
+  })
+
+  it('an injection-triggered turn/start claims nothing', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('e1'), queuedFrame('留', 'p-1'))
+    const injection = {
+      ...ev.turnStart(0, 0),
+      data: { turn: 0, trigger: { kind: 'injection', source: { kind: 'plugin', plugin: 'x' } } },
+    } as never
+    session.handleMuxEnvelope(rid('e2'), { type: 'session/event', sessionId: SID, event: injection })
+    expect(session.getSnapshot().queue).toHaveLength(1)
+  })
+
+  it('steering/message drains the source-matched steering row only', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('e1'), queuedFrame('普通', 'p-1')) // idle → non-steering
+    session.handleMuxEnvelope(rid('e3'), queuedFrame('插话', 'p-2', true))
+    // Loop-authored steering (different source) must not consume the user entry.
+    const foreignSteering = {
+      seq: 0, time: 1,
+      type: 'steering/message', surfaceOp: 'append',
+      data: {
+        turn: 0,
+        message: createUserMessage({
+          content: text('loop'),
+          source: { kind: 'plugin', plugin: 'loop' },
+        }),
+      },
+    } as never
+    session.handleMuxEnvelope(rid('e4'), { type: 'session/event', sessionId: SID, event: foreignSteering })
+    expect(session.getSnapshot().queue).toHaveLength(2)
+    const matchedSteering = {
+      seq: 1, time: 2,
+      type: 'steering/message', surfaceOp: 'append',
+      data: {
+        turn: 0,
+        message: createUserMessage({
+          content: text('插话'),
+          source: { kind: 'user', rpcId: rid('p-2') },
+        }),
+      },
+    } as never
+    session.handleMuxEnvelope(rid('e5'), { type: 'session/event', sessionId: SID, event: matchedSteering })
+    expect(session.getSnapshot().queue.map(r => r.key)).toEqual(['p-1'])
+  })
+
+  it('a leave-running flip sweeps the whole mirror (cancel/terminal-drop cover)', () => {
+    const session = makeSession()
+    session.handleRunning(true)
+    session.handleMuxEnvelope(rid('e1'), queuedFrame('一', 'p-1'))
+    session.handleMuxEnvelope(rid('e2'), queuedFrame('二', 'p-2'))
+    session.handleRunning(false)
+    expect(session.getSnapshot().queue).toEqual([])
+  })
+
+  it('a stale not-running relay on an idle session still sweeps replayed rows', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('e1'), queuedFrame('孤儿', 'p-1'))
+    session.handleRunning(false) // running already false: equality path must not skip the sweep
+    expect(session.getSnapshot().queue).toEqual([])
+  })
+})
+
+describe('queue reconnect semantics', () => {
+  it('session/subscribed re-baselines the mirror: stale rows drop, the following snapshot lands fresh', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('e1'), queuedFrame('旧连接', 'p-old'))
+    // New mux generation: subscribed arrives first on the same stream...
+    session.handleMuxEnvelope(rid('e2'), { type: 'session/subscribed', sessionId: SID, lastSeq: 10 })
+    expect(session.getSnapshot().queue).toEqual([])
+    // ...then the queue snapshot replays the live inbox.
+    session.handleMuxEnvelope(rid('e3'), queuedFrame('新基线', 'p-new'))
+    expect(session.getSnapshot().queue.map(r => r.key)).toEqual(['p-new'])
+  })
+
+  it('resync must NOT clear the mirror (regression: onConnected races the mux baseline)', async () => {
+    const session = makeSession()
+    // Reconnect ordering that broke: mux opened first and already delivered
+    // the fresh generation's baseline; host stream (and with it onConnected →
+    // resync) lands after. The host never resends — clearing here left the
+    // dock empty until the next enqueue.
+    session.handleMuxEnvelope(rid('e1'), { type: 'session/subscribed', sessionId: SID, lastSeq: 5 })
+    session.handleMuxEnvelope(rid('e2'), queuedFrame('新基线', 'p-fresh'))
+    await session.resync()
+    expect(session.getSnapshot().queue.map(r => r.key)).toEqual(['p-fresh'])
+  })
+
+  it('replayed steering retires without a replayed turn/start', () => {
+    const session = makeSession()
+    session.handleMuxEnvelope(rid('e1'), { type: 'session/subscribed', sessionId: SID, lastSeq: 5 })
+    session.handleMuxEnvelope(rid('e2'), queuedFrame('重连插话', 'p-steer', true))
+    const committed = {
+      seq: 6, time: 2,
+      type: 'steering/message', surfaceOp: 'append',
+      data: {
+        turn: 1,
+        message: createUserMessage({
+          content: text('重连插话'),
+          source: { kind: 'user', rpcId: rid('p-steer') },
+        }),
+      },
+    } as never
+    session.handleMuxEnvelope(rid('e3'), { type: 'session/event', sessionId: SID, event: committed })
+    expect(session.getSnapshot().queue).toEqual([])
+  })
+})
+
+describe('manager buffering of queued frames', () => {
+  it('buffers session/queued for uninstantiated sessions and replays before the running sync', () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    manager.handleMuxEnvelope({ rpcId: rid('b1'), payload: queuedFrame('预热', 'p-b1') })
+    // Instantiation replays the buffer; no summary exists, so no running sweep runs.
+    const session = manager.get(SID)
+    expect(session.getSnapshot().queue.map(r => r.key)).toEqual(['p-b1'])
+    // The buffer is consumed: a second get must not double-replay.
+    expect(manager.get(SID).getSnapshot().queue).toHaveLength(1)
+  })
+
+  it('a not-running list summary sweeps replayed rows at instantiation', async () => {
+    const api = new FakeApiClient()
+    api.onList = () => Promise.resolve(ok([{ sessionId: SID, updatedAt: 1, running: false }]))
+    const manager = new SessionManager(api)
+    await manager.refreshList()
+    manager.handleMuxEnvelope({ rpcId: rid('b2'), payload: queuedFrame('该扫掉', 'p-b2') })
+    expect(manager.get(SID).getSnapshot().queue).toEqual([])
+  })
+
+  it('subscribed re-baselines the uninstantiated buffer: stale queued frames drop, non-queue frames survive (regression: reconnect duplication)', () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    // Generation 1 baseline lands while the session is uninstantiated, along
+    // with a pending approval (never re-derivable from history).
+    manager.handleMuxEnvelope({ rpcId: rid('g1a'), payload: queuedFrame('第一代', 'p-g1') })
+    manager.handleMuxEnvelope({
+      rpcId: rid('g1b'),
+      payload: { type: 'approval/requested', sessionId: SID, approvalId: 'ap-1' as never, toolName: 'bash' },
+    })
+    // Reconnect: generation 2 replays subscribed + the SAME live queue entry.
+    manager.handleMuxEnvelope({ rpcId: rid('g2a'), payload: { type: 'session/subscribed', sessionId: SID, lastSeq: 3 } })
+    manager.handleMuxEnvelope({ rpcId: rid('g2b'), payload: queuedFrame('第一代', 'p-g1') })
+    const snapshot = manager.get(SID).getSnapshot()
+    // One queue row (no duplicate batch); the approval survived the re-baseline.
+    expect(snapshot.queue.map(r => r.key)).toEqual(['p-g1'])
+    expect(snapshot.pending.map(p => p.kind)).toEqual(['approval'])
+  })
+})
+
+/** ok wrapper with a typed items payload (the shared helper pins value to never[]). */
+function ok(items: { sessionId: SessionId; updatedAt: number; running: boolean }[]) {
+  return { rpcId: rid(`ok-${items.length}`), result: { ok: true as const, value: { items: items as never[] } } }
+}

packages/client/runtime/tests/scope.spec.ts

@@ -0,0 +1,84 @@
+/**
+ * Agent-scope primitive spec: the actx minted by createScope carries the
+ * tag and the dispatch filter itself, so plain cordis dispatch with the actx
+ * as subject routes by agent — same-agent tagged listeners receive,
+ * foreign-agent ones are filtered out, untagged listeners hear everything,
+ * and a subject-less root dispatch stays unfiltered. Scope-owned listeners
+ * dispose with the fiber.
+ */
+import { Context } from 'cordis'
+import { describe, expect, it } from 'vitest'
+import type { SessionId } from '@deepseek-ai/dsh-client-connection/client'
+import { createScope, scopeOf } from '../src/client/agents/scope.ts'
+
+const sid = (k: string): SessionId => k as SessionId
+
+declare module 'cordis' {
+  interface Events {
+    /**
+     * Test-only routed probe event.
+     * @param payload - marker payload.
+     * @mode bail
+     */
+    'test/scope-probe'(payload: { from: string }): true | undefined
+  }
+}
+
+function bench() {
+  const root = new Context()
+  const a = createScope(root, sid('a'))
+  const b = createScope(root, sid('b'))
+  const seen: string[] = []
+  const listen = (label: string, ctx: Context, answer?: true) => {
+    ctx.on('test/scope-probe', (payload) => {
+      seen.push(`${label}:${payload.from}`)
+      return answer
+    })
+  }
+  return { root, a, b, seen, listen }
+}
+
+describe('createScope', () => {
+  it('tags the ctx (scopeOf) and leaves the root untagged', () => {
+    const { root, a } = bench()
+    expect(scopeOf(a.ctx)).toBe(sid('a'))
+    expect(scopeOf(root)).toBeUndefined()
+  })
+
+  it('scoped dispatch reaches same-session and untagged listeners, never a foreign session', () => {
+    const { root, a, b, seen, listen } = bench()
+    listen('a', a.ctx)
+    listen('b', b.ctx)
+    listen('root', root)
+    a.ctx.bail(a.ctx, 'test/scope-probe', { from: 'a' })
+    expect(seen).toEqual(['a:a', 'root:a'])
+    seen.length = 0
+    b.ctx.emit(b.ctx, 'test/scope-probe', { from: 'b' })
+    expect(seen).toEqual(['b:b', 'root:b'])
+  })
+
+  it('bail answers the first same-scope listener and skips filtered foreign ones', () => {
+    const { a, b, listen } = bench()
+    listen('b', b.ctx, true) // registered first, but foreign → filtered out
+    expect(a.ctx.bail(a.ctx, 'test/scope-probe', { from: 'a' })).toBeUndefined()
+    listen('a', a.ctx, true)
+    expect(a.ctx.bail(a.ctx, 'test/scope-probe', { from: 'a' })).toBe(true)
+  })
+
+  it('a subject-less root dispatch is unfiltered (every listener hears it)', () => {
+    const { root, a, b, seen, listen } = bench()
+    listen('a', a.ctx)
+    listen('b', b.ctx)
+    listen('root', root)
+    root.emit('test/scope-probe', { from: 'root' })
+    expect(seen).toEqual(['a:root', 'b:root', 'root:root'])
+  })
+
+  it('fiber disposal removes scope-owned listeners', async () => {
+    const { a, seen, listen } = bench()
+    listen('a', a.ctx)
+    await a.fiber.dispose()
+    a.ctx.emit(a.ctx, 'test/scope-probe', { from: 'late' })
+    expect(seen).toEqual([])
+  })
+})

packages/client/runtime/tests/session.spec.ts

@@ -75,7 +75,11 @@ describe('open', () => {
     const page = plainTurn(10, 0, '早', '安')
     session.handleMuxEnvelope('r1' as never, { type: 'session/event', sessionId: SID, event: ev.turnStart(15, 1) })
     session.handleMuxEnvelope('r2' as never, { type: 'session/event', sessionId: SID, event: ev.user(16, '插进来的') })
-    gate.resolve(ok({ events: entries(page) as never[], hasMore: false }))
+    gate.resolve(ok({
+      events: entries(page) as never[],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'deepseek-v4-flash' },
+    }))
     await opening
     const seqs = session.getSnapshot().nodes.map(n => n.seq)
     // Overlapping seq-15 frame (== page tail turn/end) was dropped; 16 appended once.
@@ -83,6 +87,7 @@ describe('open', () => {
   })
 })
 
+
 describe('live event path', () => {
   async function opened(events: SessionEvent[] = plainTurn(0, 0, 'a', 'b')) {
     const { api, session } = makeSession()
@@ -99,6 +104,28 @@ describe('live event path', () => {
     expect(session.getSnapshot().nodes).toEqual(before.nodes)
   })
 
+  it('materializes a command node from live lifecycle frames and reproduces it from a history window', async () => {
+    // Live path: run mints an executing node, done settles it in the flow.
+    const { session } = await opened()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.commandRun(6, 'cmd-live', 'plan'))
+    let command = session.getSnapshot().nodes.at(-1)
+    expect(command).toMatchObject({ kind: 'command', name: 'plan', args: '', outcome: null })
+    feed(ev.commandDone(7, 'cmd-live', 'success', '已进入 plan mode'))
+    command = session.getSnapshot().nodes.at(-1)
+    expect(command).toMatchObject({ kind: 'command', seq: 6, outcome: { kind: 'success', text: '已进入 plan mode' } })
+
+    // Replay path (refresh): the same pair inside the history window folds identically.
+    const replayed = await opened([
+      ...plainTurn(0, 0, 'a', 'b'),
+      ev.commandRun(6, 'cmd-live', 'plan'),
+      ev.commandDone(7, 'cmd-live', 'success', '已进入 plan mode'),
+    ])
+    expect(replayed.session.getSnapshot().nodes.at(-1)).toMatchObject({
+      kind: 'command', seq: 6, name: 'plan', outcome: { kind: 'success', text: '已进入 plan mode' },
+    })
+  })
+
   it('accumulates chunks into partial, then finalize swaps partial out as the node lands', async () => {
     const { session } = await opened()
     const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
@@ -210,26 +237,44 @@ describe('paging', () => {
     api.onHistory = () => gate.promise
     const first = session.loadOlder()
     const second = session.loadOlder()
-    gate.resolve(ok({ events: entries(plainTurn(0, 0, 'a', 'b')) as never[], hasMore: false }))
+    gate.resolve(ok({
+      events: entries(plainTurn(0, 0, 'a', 'b')) as never[],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'deepseek-v4-flash' },
+    }))
     await Promise.all([first, second])
     expect(api.callsOf('session.history')).toHaveLength(2) // open + one page, not two
   })
 })
 
 describe('prompt and cancel errors', () => {
-  it('sends content through session.prompt with the mode passed through', async () => {
+  it('sends content through session.prompt; composerPhase steps blank → engaging synchronously at send entry', async () => {
     const { api, session } = makeSession()
-    const result = await session.prompt([{ type: 'text', text: '要发的' }], 'queue')
+    // The blank → engaging edge fires before the RPC settles: the first-send
+    // flow reads the phase on the session area's first frame to keep the
+    // guidance hero from flashing back in.
+    expect(session.getSnapshot().composerPhase).toBe('blank')
+    const inFlight = session.prompt([{ type: 'text', text: '要发的' }], 'queue')
+    expect(session.getSnapshot().composerPhase).toBe('engaging')
+    const result = await inFlight
     expect(result.ok).toBe(true)
+    // Monotone: settlement alone does not step the phase anywhere.
+    expect(session.getSnapshot().composerPhase).toBe('engaging')
     expect(api.callsOf('session.prompt')).toMatchObject([{ sessionId: SID, mode: 'queue', content: [{ type: 'text', text: '要发的' }] }])
+    // First content lands (running turn): engaging → active.
+    session.handleRunning(true)
+    expect(session.getSnapshot().composerPhase).toBe('active')
   })
 
-  it('business failure lands in promptError with op=send', async () => {
+  it('business failure lands in promptError with op=send; the phase stays engaging (retry, no hero bounce)', async () => {
     const { api, session } = makeSession()
     api.onPrompt = () => Promise.resolve(err({ code: 'agent-busy', message: 'busy', details: { reason: 'x' } }))
     const result = await session.prompt([{ type: 'text', text: '失败的' }], 'queue')
     expect(result.ok).toBe(false)
     expect(session.getSnapshot().promptError).toMatchObject({ op: 'send', error: { code: 'agent-busy' } })
+    // Failed first prompt: composer + error strip is the retry surface —
+    // blank is unreachable once a send was initiated.
+    expect(session.getSnapshot().composerPhase).toBe('engaging')
   })
 
   it('lands cancel failures in promptError with op=stop', async () => {
@@ -482,7 +527,11 @@ describe('remaining branches', () => {
     const opening = session.open()
     api.onHistory = () => histResponse(plainTurn(6, 1, '新', '代'))
     const resynced = session.resync()
-    stale.resolve(ok({ events: entries(plainTurn(0, 0, '旧', '代')) as never[], hasMore: false })) // success, but its generation is gone
+    stale.resolve(ok({
+      events: entries(plainTurn(0, 0, '旧', '代')) as never[],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'stale' },
+    })) // success, but its generation is gone
     await Promise.all([opening, resynced])
     expect(session.getSnapshot().nodes.map(n => n.seq)).toEqual([7, 9]) // only the fresh generation's window
   })
@@ -501,7 +550,11 @@ describe('remaining branches', () => {
     const opening = session.open() // triggers the second pull, which parks
     await vi.waitFor(() => { expect(call).toBe(2) })
     const resynced = session.resync()
-    secondPull.resolve(ok({ events: entries([...plainTurn(0, 0, 'a', 'b'), ...plainTurn(6, 1, 'c', 'd')]) as never[], hasMore: false }))
+    secondPull.resolve(ok({
+      events: entries([...plainTurn(0, 0, 'a', 'b'), ...plainTurn(6, 1, 'c', 'd')]) as never[],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'stale' },
+    }))
     await Promise.all([opening, resynced])
     expect(session.getSnapshot().openState).toBe('open')
   })
@@ -515,7 +568,11 @@ describe('remaining branches', () => {
     session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event: ev.user(9, '洞') }) // starts repairGap
     api.onHistory = () => histResponse(plainTurn(6, 1, 'c', 'd'))
     const resynced = session.resync() // bumps the generation
-    repairPull.resolve(ok({ events: entries(plainTurn(0, 0, '旧', '页')) as never[], hasMore: false })) // repair result: stale, dropped
+    repairPull.resolve(ok({
+      events: entries(plainTurn(0, 0, '旧', '页')) as never[],
+      hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'stale' },
+    })) // repair result: stale, dropped
     await resynced
     expect(session.getSnapshot().nodes.map(n => n.seq)).toEqual([7, 9])
   })
@@ -559,6 +616,7 @@ describe('remaining branches', () => {
         { event: ev.toolResult(7, 1, 'h1', 'done'), view: { for: 'result', view: { card: 'generic', title: '历史果' } } },
       ] as never[],
       hasMore: false,
+      modelTarget: { provider: 'deepseek', model: 'deepseek-v4-flash' },
     }))
     await session.open()
     expect(session.getSnapshot().nodes.at(-1)).toMatchObject({
@@ -630,6 +688,95 @@ describe('resync', () => {
   })
 })
 
+describe('run_code sub-dispatch indexing', () => {
+  it('a start event lands as a running-shaped sub-call and its settle replaces it in place', async () => {
+    const { api, session } = makeSession()
+    api.onHistory = () => histResponse(plainTurn(0, 0, '问', '答'))
+    await session.open()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.turnStart(6, 1))
+    feed(ev.toolCall(7, 1, 'p1', 'run_code', '{"code":"1","description":"d"}'))
+    feed(ev.codeDispatchStart(8, 'p1', 1, 'bash', { command: 'sleep' }))
+    feed(ev.codeDispatchStart(9, 'p1', 2, 'read', { path: 'a.txt' }))
+    const live = session.getSnapshot().codeDispatches.get('p1')
+    expect(live).toHaveLength(2)
+    // Running shape (no 'kind'): the exact RunningToolCall form native rows use.
+    expect(live?.[0]).toMatchObject({ callId: 'p1:code:1', name: 'bash', argsRaw: '{"command":"sleep"}' })
+    expect(live?.[0] !== undefined && 'kind' in live[0]).toBe(false)
+    // Settle out of order (parallel run): #2 first — replaces in place, keeping start order.
+    feed(ev.codeDispatch(10, 'p1', 2, 'read', { path: 'a.txt' }, 'alpha'))
+    const mixed = session.getSnapshot().codeDispatches.get('p1')
+    expect(mixed?.map(sub => 'kind' in sub)).toEqual([false, true])
+    expect(mixed?.[1]).toMatchObject({ callId: 'p1:code:2', content: [{ type: 'text', text: 'alpha' }] })
+    // The settle carries the paired start's time as callTime (duration source).
+    feed(ev.codeDispatch(11, 'p1', 1, 'bash', { command: 'sleep' }, 'done'))
+    const settled = session.getSnapshot().codeDispatches.get('p1')
+    expect(settled?.map(sub => 'kind' in sub)).toEqual([true, true])
+    expect(settled?.[0]).toMatchObject({ callId: 'p1:code:1', callTime: 1_700_000_000_008 })
+  })
+
+  it('indexes live tool/code-dispatch events under their parent as native-shaped result nodes', async () => {
+    const { api, session } = makeSession()
+    api.onHistory = () => histResponse(plainTurn(0, 0, '问', '答'))
+    await session.open()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.turnStart(6, 1))
+    feed(ev.toolCall(7, 1, 'p1', 'run_code', '{"code":"return 1","description":"跑一个程序"}'))
+    feed(ev.codeDispatch(8, 'p1', 1, 'bash', { command: 'ls', description: '列目录' }, 'demo.txt'))
+    feed(ev.codeDispatch(9, 'p1', 2, 'read', { path: 'a.txt' }, 'Error: ENOENT', true))
+    const subs = session.getSnapshot().codeDispatches.get('p1')
+    expect(subs).toHaveLength(2)
+    expect(subs?.[0]).toMatchObject({
+      kind: 'tool-result', callId: 'p1:code:1',
+      call: { name: 'bash', argsRaw: '{"command":"ls","description":"列目录"}' },
+      // The settle event carries no start time: callTime stays null (never a
+      // fabricated zero-duration).
+      callTime: null,
+      isError: false, content: [{ type: 'text', text: 'demo.txt' }],
+    })
+    expect(subs?.[1]).toMatchObject({ callId: 'p1:code:2', isError: true })
+    // No paired start in the window: duration is UNKNOWN (null), never a
+    // fabricated zero-duration span.
+    expect(subs?.[0]).toMatchObject({ callTime: null })
+    // Sub-dispatches never join the surface flow.
+    expect(session.getSnapshot().nodes.some(n => n.kind === 'tool-result' && n.callId.includes(':code:'))).toBe(false)
+  })
+
+  it('rebuilds the same index from a history window (replay parity)', async () => {
+    const { api, session } = makeSession()
+    api.onHistory = () => histResponse([
+      ...plainTurn(0, 0, '问', '答'),
+      ev.turnStart(6, 1),
+      ev.toolCall(7, 1, 'p1', 'run_code', '{"code":"return 1","description":"跑一个程序"}'),
+      ev.codeDispatch(8, 'p1', 1, 'bash', { command: 'ls' }, 'demo.txt'),
+      ev.toolResult(9, 1, 'p1', '{"done":true}'),
+      ev.turnEnd(10, 1),
+    ])
+    await session.open()
+    const subs = session.getSnapshot().codeDispatches.get('p1')
+    expect(subs).toHaveLength(1)
+    expect(subs?.[0]).toMatchObject({ callId: 'p1:code:1', call: { name: 'bash' } })
+  })
+
+  it('keeps the dispatch map reference across unrelated changes and swaps it on a new dispatch', async () => {
+    const { api, session } = makeSession()
+    api.onHistory = () => histResponse(plainTurn(0, 0, '稳', '定'))
+    await session.open()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.turnStart(6, 1))
+    feed(ev.toolCall(7, 1, 'p1', 'run_code', '{"code":"1","description":"d"}'))
+    feed(ev.codeDispatch(8, 'p1', 1, 'bash', { command: 'ls' }, 'x'))
+    const before = session.getSnapshot()
+    feed(ev.chunkStart(9, 1))
+    feed(ev.chunkText(10, 1, '流式'))
+    const after = session.getSnapshot()
+    expect(after.codeDispatches).toBe(before.codeDispatches)
+    feed(ev.codeDispatch(11, 'p1', 2, 'read', { path: 'a' }, 'y'))
+    expect(session.getSnapshot().codeDispatches).not.toBe(after.codeDispatches)
+    expect(session.getSnapshot().codeDispatches.get('p1')).toHaveLength(2)
+  })
+})
+
 describe('reference stability (the memo contract)', () => {
   it('keeps unchanged node references across an append and swaps the snapshot object', async () => {
     const { api, session } = makeSession()

packages/client/runtime/tests/sessions-service.spec.ts

@@ -9,8 +9,8 @@
 import { Context } from 'cordis'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import type { SessionId } from '@deepseek-ai/dsh-client-connection/client'
-import { SessionsService, scopeOf } from '../src/client/sessions/service.ts'
-import { FakeApiClient, ok } from './fake-api.ts'
+import { SessionCreateError, SessionsService, scopeOf } from '../src/client/sessions/service.ts'
+import { FakeApiClient, deferred, ok } from './fake-api.ts'
 
 const sid = (s: string): SessionId => s as SessionId
 
@@ -28,24 +28,26 @@ function bench(): Bench {
 }
 
 /** Refresh the manager list from programmable rows and flush the microtask batch. */
-async function feedList(b: Bench, rows: { id: string; cwd?: string; parentId?: string; running?: boolean }[]): Promise<void> {
+type FeedRow = { id: string; cwd?: string; parentId?: string; running?: boolean; blank?: boolean }
+
+async function feedList(b: Bench, rows: FeedRow[]): Promise<void> {
   b.api.onList = () => Promise.resolve(ok({
     items: rows.map(r => ({
-      sessionId: sid(r.id), updatedAt: 1, running: r.running ?? false,
+      sessionId: sid(r.id), updatedAt: 1, running: r.running ?? false, blank: r.blank ?? false,
       ...(r.cwd !== undefined ? { cwd: r.cwd } : {}),
       ...(r.parentId !== undefined ? { parentSessionId: sid(r.parentId) } : {}),
     })),
   }) as never)
-  await b.svc.manager.refreshList()
+  await b.svc.refresh()
   await Promise.resolve() // manager notifier flush
 }
 
 describe('list store projection', () => {
   it('projects durable titles separately from cwd/id display fallbacks and parent links', async () => {
     const b = bench()
-    b.svc.manager.handleMuxEnvelope({
+    b.svc.handleMuxEnvelope({
       rpcId: 'title' as never,
-      payload: { type: 'session/title', sessionId: sid('s1'), title: 'Durable title', eventSeq: 2, updatedAt: 3 },
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'title', value: 'Durable title', seq: 2 } as never,
     })
     await feedList(b, [
       { id: 's1', cwd: '/home/u/proj-a/' },
@@ -61,7 +63,7 @@ describe('list store projection', () => {
   it('reflects live increments (host stream via manager) into the store', async () => {
     const b = bench()
     await feedList(b, [{ id: 's1' }])
-    b.svc.manager.handleHostEnvelope({ rpcId: 'r1' as never, payload: { type: 'host/session-added', sessionId: sid('s2') } as never })
+    b.svc.handleHostEnvelope({ rpcId: 'r1' as never, payload: { type: 'host/session-added', blank: true, sessionId: sid('s2') } as never })
     await Promise.resolve()
     expect(b.svc.list.getSnapshot().ids).toContain('s2')
   })
@@ -77,7 +79,8 @@ describe('scope tree', () => {
     expect(scopeOf(scoped as Context)).toBe('s1')
     expect(scopeOf(b.ctx)).toBeUndefined()
     const binding = b.svc.binding(sid('s1'))
-    expect(binding?.session).toBe(b.svc.manager.get(sid('s1')))
+    b.svc.open(sid('s1'))
+    expect(binding?.session).toBe(b.svc.currentProvideInfo.getSnapshot().hooks['session'])
     expect(b.svc.binding(sid('s1'))).toBe(binding)
     expect(binding?.ctx).toBe(scoped)
   })
@@ -181,25 +184,82 @@ describe('current selection (migrated from ui-layout, arbitrated into the list s
 })
 
 describe('cell (render-layer session kit)', () => {
-  it('resolves an identity-stable {sessionId, session} cell; unknown ids yield undefined', async () => {
+  it('resolves an identity-stable {sessionId, session} cell through the current projection', async () => {
     const b = bench()
     await feedList(b, [{ id: 's1' }])
-    const cell = b.svc.cell('s1')
-    expect(cell).toBeDefined()
-    expect(cell?.sessionId).toBe('s1')
-    // Bare-source form (store migration): the cell carries the Session
-    // observable itself; hook binding happens in the React machinery.
-    expect(cell?.session).toBe(b.svc.manager.get(sid('s1')))
-    expect(b.svc.cell('s1')).toBe(cell)
-    expect(b.svc.cell('ghost')).toBeUndefined()
+    b.svc.open(sid('s1'))
+    const info = b.svc.currentProvideInfo.getSnapshot()
+    expect(info.sessionId).toBe('s1')
+    // The bundle carries bare observables; hook binding happens in React.
+    expect(info.hooks['session']).toBe(b.svc.binding(sid('s1'))?.session)
+    // Re-staging the same id republishes nothing: identity holds.
+    b.svc.open(sid('s1'))
+    expect(b.svc.currentProvideInfo.getSnapshot()).toBe(info)
   })
 
-  it('cell()/binding() are pure resolution: no staging, no deferred sweep', async () => {
+  it('currentProvideInfo follows selection: absent projection ↔ definite bundle, notified on each move', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1' }, { id: 's2' }])
+    const absent = b.svc.currentProvideInfo.getSnapshot()
+    expect(absent.sessionId).toBeUndefined()
+    expect(Object.hasOwn(absent.hooks, 'session')).toBe(true)
+    const notified = vi.fn()
+    b.svc.currentProvideInfo.subscribe(notified)
+    b.svc.open(sid('s1'))
+    const s1Bundle = b.svc.currentProvideInfo.getSnapshot()
+    expect(s1Bundle.sessionId).toBe('s1')
+    expect(s1Bundle.hooks['session']).toBe(b.svc.binding(sid('s1'))?.session)
+    expect(notified).toHaveBeenCalledTimes(1)
+    b.svc.open(sid('s2'))
+    const s2Bundle = b.svc.currentProvideInfo.getSnapshot()
+    expect(s2Bundle.sessionId).toBe('s2')
+    expect(s2Bundle).not.toBe(s1Bundle)
+    expect(notified).toHaveBeenCalledTimes(2)
+    b.svc.clear()
+    await Promise.resolve() // clearSelection projects through the manager notifier
+    expect(b.svc.currentProvideInfo.getSnapshot().sessionId).toBeUndefined()
+  })
+
+  it('a provider roster change under a stable current id republishes the bundle', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1' }])
+    b.svc.open(sid('s1'))
+    const before = b.svc.currentProvideInfo.getSnapshot()
+    const notified = vi.fn()
+    b.svc.currentProvideInfo.subscribe(notified)
+    const source = { getSnapshot: () => 'live', subscribe: () => () => {} }
+    const dispose = b.svc.provide({
+      hooks: ['extra'],
+      props: ['marker'],
+      resolve: () => ({ hooks: { extra: source }, props: { marker: 7 } }),
+    })
+    const added = b.svc.currentProvideInfo.getSnapshot()
+    expect(added).not.toBe(before)
+    expect(added).toMatchObject({ sessionId: 's1', props: { marker: 7 } })
+    expect(added.hooks['extra']).toBe(source)
+    expect(notified).toHaveBeenCalledTimes(1)
+    dispose()
+    const removed = b.svc.currentProvideInfo.getSnapshot()
+    expect(removed).not.toBe(added)
+    expect(Object.hasOwn(removed.hooks, 'extra')).toBe(false)
+    expect(notified).toHaveBeenCalledTimes(2)
+  })
+
+  it('an unsubscribed currentProvideInfo listener stops receiving notifications', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1' }])
+    const notified = vi.fn()
+    const off = b.svc.currentProvideInfo.subscribe(notified)
+    off()
+    b.svc.open(sid('s1'))
+    expect(notified).not.toHaveBeenCalled()
+  })
+
+  it('binding() is pure resolution: no staging, no deferred sweep', async () => {
     const b = bench()
     await feedList(b, [{ id: 's1' }, { id: 's2' }])
     b.svc.open(sid('s1')) // staged
-    b.svc.cell('s2') // resolution only — must NOT move the stage
-    b.svc.binding(sid('s2'))
+    b.svc.binding(sid('s2')) // resolution only — must NOT move the stage
     await feedList(b, [{ id: 's2' }]) // s1 removed: still staged → deferred, scope survives
     expect(b.svc.scope(sid('s1'))).toBeDefined()
   })
@@ -210,7 +270,6 @@ describe('cell (render-layer session kit)', () => {
     const historyCalls = () => b.api.calls.filter(c => c.method === 'session.history')
     // Resolution is addressing, not staging: no window pull.
     b.svc.scope(sid('s1'))
-    b.svc.cell('s1')
     b.svc.binding(sid('s1'))
     expect(historyCalls()).toHaveLength(0)
     b.svc.open(sid('s1'))
@@ -285,36 +344,157 @@ describe('ancestry', () => {
 })
 
 describe('create', () => {
-  it('returns the new id on ok and throws a coded error on failure', async () => {
+  it('passes a preallocated id and preserves it on ordinary failure', async () => {
     const b = bench()
     b.api.onCreate = () => Promise.resolve(ok({ sessionId: sid('fresh') }))
-    await expect(b.svc.create({ cwd: '/w' })).resolves.toBe('fresh')
+    await expect(b.svc.create({ cwd: '/w', sessionId: sid('fresh') })).resolves.toBe('fresh')
+    expect(b.api.callsOf('session.create')).toEqual([{ cwd: '/w', sessionId: 'fresh' }])
     b.api.onCreate = () => Promise.resolve({
       rpcId: 'e' as never,
       result: { ok: false as const, error: { code: 'internal' as const, message: '爆了', details: {} } },
     } as never)
-    await expect(b.svc.create()).rejects.toThrow(/internal: 爆了/)
+    const failure = await b.svc.create({ sessionId: sid('candidate') }).catch((error: unknown) => error)
+    expect(failure).toBeInstanceOf(SessionCreateError)
+    expect(failure).toMatchObject({
+      requestedSessionId: 'candidate',
+      rpcError: { code: 'internal', message: '爆了' },
+    })
+  })
+
+  it('resolves with the session already listed and binding-resolvable (no flush wait)', async () => {
+    const b = bench()
+    b.api.onCreate = () => Promise.resolve(ok({ sessionId: sid('born') }))
+    const born = await b.svc.create({ workspaceId: 'ws' as never })
+    // Synchronously after resolution — the draft hand-off contract: the
+    // create echo IS the entity entering the client's view (blank row +
+    // resolvable scope/binding), no notifier flush in between.
+    expect(b.svc.list.getSnapshot().byId[born]).toMatchObject({ id: 'born', blank: true })
+    expect(b.svc.binding(born)).toBeDefined()
+    expect(b.svc.scope(born)).toBeDefined()
+  })
+
+  it('lists the published id after Workspace attachment fails (publication precedes attachment)', async () => {
+    const b = bench()
+    b.api.onCreate = () => Promise.resolve({
+      rpcId: 'attach' as never,
+      result: {
+        ok: false,
+        error: {
+          code: 'workspace-attach-failed', message: 'ledger unavailable',
+          details: { sessionId: sid('published'), workspaceId: 'ws' },
+        },
+      },
+    } as never)
+    const failure = await b.svc.create({
+      workspaceId: 'ws' as never,
+      sessionId: sid('published'),
+    }).catch((error: unknown) => error)
+    await Promise.resolve()
+    expect(failure).toBeInstanceOf(SessionCreateError)
+    expect(failure).toMatchObject({
+      requestedSessionId: 'published',
+      rpcError: { code: 'workspace-attach-failed' },
+    })
+    expect(b.svc.list.getSnapshot().byId[sid('published')]).toMatchObject({ id: 'published', blank: true })
   })
 })
 
-describe('createWorkspace', () => {
-  it('joins host.describe cwd with the name and creates there', async () => {
+describe('scope lifecycle rides the list mirror (entity parity: no client-side pre-birth)', () => {
+  it('a session-added frame births the row (blank) and makes the scope resolvable; removal prunes it', async () => {
     const b = bench()
-    b.api.onDescribe = () => Promise.resolve(ok({ version: '0', cwd: '/host/root', attachedSessions: 0 }))
-    b.api.onCreate = () => Promise.resolve(ok({ sessionId: sid('ws') }))
-    await expect(b.svc.createWorkspace('My Proj')).resolves.toBe('ws')
-    expect(b.api.callsOf('session.create')).toEqual([{ cwd: '/host/root/My Proj' }])
+    await feedList(b, [])
+    expect(b.svc.scope(sid('s-new'))).toBeUndefined() // not in view: no scope, no exceptions
+    b.svc.handleHostEnvelope({
+      rpcId: 'add' as never,
+      payload: { type: 'host/session-added', sessionId: sid('s-new'), blank: true, cwd: '/w/a' } as never,
+    })
+    await Promise.resolve()
+    const scoped = b.svc.scope(sid('s-new'))
+    expect(scoped).toBeDefined()
+    expect(scopeOf(scoped as Context)).toBe('s-new')
+    b.svc.handleHostEnvelope({
+      rpcId: 'rm' as never,
+      payload: { type: 'host/session-removed', sessionId: sid('s-new') },
+    })
+    await Promise.resolve()
+    expect(b.svc.scope(sid('s-new'))).toBeUndefined()
+  })
+})
+
+describe('blank mirror', () => {
+  it('flips blank=false from the running:true status frame (cross-client conversion)', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1', blank: true }])
+    expect(b.svc.list.getSnapshot().byId[sid('s1')]).toMatchObject({ blank: true })
+    b.svc.handleHostEnvelope({
+      rpcId: 'st' as never,
+      payload: { type: 'host/session-status', sessionId: sid('s1'), running: true },
+    })
+    await Promise.resolve()
+    expect(b.svc.list.getSnapshot().byId[sid('s1')]).toMatchObject({ blank: false, running: true })
+    // The instantiated Session mirrors the same flip.
+    expect(b.svc.binding(sid('s1'))?.session.getSnapshot().blank).toBe(false)
   })
 
-  it('rejects empty names and path separators; surfaces describe failures', async () => {
+  it('flips blank=false on prompt ACCEPTANCE, not on the attempt', async () => {
     const b = bench()
-    await expect(b.svc.createWorkspace('  ')).rejects.toThrow(/name is required/)
-    await expect(b.svc.createWorkspace('a/b')).rejects.toThrow(/path separators/)
-    b.api.onDescribe = () => Promise.resolve({
-      rpcId: 'e' as never,
-      result: { ok: false as const, error: { code: 'internal' as const, message: 'down', details: {} } },
+    await feedList(b, [{ id: 's1', blank: true, cwd: '/w/a' }])
+    const session = b.svc.binding(sid('s1'))!.session
+    expect(session.getSnapshot().blank).toBe(true)
+    const gate = deferred<Awaited<ReturnType<FakeApiClient['onPrompt']>>>()
+    b.api.onPrompt = () => gate.promise
+    const send = session.prompt([{ type: 'text', text: 'hi' }], 'queue')
+    // In flight: still blank (the flip point is the success response, which
+    // proves the user message reached the host log).
+    expect(session.getSnapshot().blank).toBe(true)
+    gate.resolve(ok({ accepted: true as const }))
+    await send
+    expect(session.getSnapshot().blank).toBe(false)
+    await Promise.resolve()
+    expect(b.svc.list.getSnapshot().byId[sid('s1')]).toMatchObject({ blank: false })
+  })
+
+  it('keeps a rejected first prompt blank: hidden and still reusable', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1', blank: true, cwd: '/w/a' }])
+    const session = b.svc.binding(sid('s1'))!.session
+    b.api.onPrompt = () => Promise.resolve({
+      rpcId: 'busy' as never,
+      result: { ok: false as const, error: { code: 'internal' as const, message: 'agent busy', details: {} } },
     } as never)
-    await expect(b.svc.createWorkspace('ok')).rejects.toThrow(/host.describe failed/)
+    const result = await session.prompt([{ type: 'text', text: 'hi' }], 'queue')
+    expect(result.ok).toBe(false)
+    // No flip on failure: local stays aligned with the host authority
+    // (events.length still 0), so the session stays hidden and reusable.
+    expect(session.getSnapshot().blank).toBe(true)
+    await Promise.resolve()
+    expect(b.svc.list.getSnapshot().byId[sid('s1')]).toMatchObject({ blank: true })
+  })
+
+  it('takes session-added blank=true as the hidden birth and list blank as reconnect authority', async () => {
+    const b = bench()
+    await feedList(b, [])
+    b.svc.handleHostEnvelope({
+      rpcId: 'add' as never,
+      payload: { type: 'host/session-added', sessionId: sid('s-new'), blank: true, cwd: '/w/a' } as never,
+    })
+    await Promise.resolve()
+    expect(b.svc.list.getSnapshot().byId[sid('s-new')]).toMatchObject({ blank: true })
+    // Reconnect re-pull: the summary's blank=false wins (authoritative alignment).
+    await feedList(b, [{ id: 's-new', blank: false, cwd: '/w/a' }])
+    expect(b.svc.list.getSnapshot().byId[sid('s-new')]).toMatchObject({ blank: false })
+  })
+
+  it('never re-blanks: a stale blank=true summary cannot hide an engaged session', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1', blank: true }])
+    const session = b.svc.binding(sid('s1'))!.session
+    await session.prompt([{ type: 'text', text: 'hi' }], 'queue')
+    await Promise.resolve()
+    expect(b.svc.list.getSnapshot().byId[sid('s1')]).toMatchObject({ blank: false })
+    // The next list pull still claims blank (host hasn't logged the message yet).
+    await feedList(b, [{ id: 's1', blank: true }])
+    expect(b.svc.binding(sid('s1'))?.session.getSnapshot().blank).toBe(false)
   })
 })
 

packages/client/runtime/tests/slots-service.spec.ts

@@ -85,19 +85,25 @@ function captureHost(bench: Bench, children?: object): SlotRendererHost {
   })
   bench.erased.register({ name: 'root', ...(children !== undefined ? { children } : {}) }, C)
   bench.ctx.reflect.provide('sessions', fakeSessions())
+  bench.ctx.reflect.provide('workspaces', fakeWorkspaces())
   bench.erased.renderSlot('root', {})
   if (host === undefined) throw new Error('renderer never received the host')
   return host
 }
 
-/** Minimal sessions face for the host seam (list observable + cell). */
+/** Minimal independent Workspace list source for the renderer host seam. */
+function fakeWorkspaces() {
+  const state = { items: [], phase: 'ready' as const }
+  return { list: { getSnapshot: () => state, subscribe: () => () => undefined } }
+}
+
+/** Minimal sessions face for the host seam (list observable + current provide projection). */
 function fakeSessions() {
   const state = { ids: [], byId: {}, current: undefined as string | undefined }
+  const absentInfo = { sessionId: undefined, hooks: { session: undefined }, props: {} }
   return {
     list: { getSnapshot: () => state, subscribe: () => () => undefined },
-    cell: (id: string) => (id === 'known'
-      ? { sessionId: id, session: { getSnapshot: () => undefined, subscribe: () => () => undefined } }
-      : undefined),
+    currentProvideInfo: { getSnapshot: () => absentInfo, subscribe: () => () => undefined },
   }
 }
 
@@ -190,9 +196,18 @@ describe('renderer install seam', () => {
     bench.erased.install({ renderRoot })
     bench.erased.register({ name: 'root' }, C)
     bench.ctx.reflect.provide('sessions', fakeSessions())
+    bench.ctx.reflect.provide('workspaces', fakeWorkspaces())
     expect(bench.erased.renderSlot('root', {})).toBe('tree')
     expect(renderRoot).toHaveBeenCalledTimes(1)
   })
+
+  it('fails before rendering when the Workspace object layer is absent', async () => {
+    const bench = await boot()
+    bench.erased.install({ renderRoot: () => null })
+    bench.erased.register({ name: 'root' }, C)
+    bench.ctx.reflect.provide('sessions', fakeSessions())
+    expect(() => bench.erased.renderSlot('root', {})).toThrow(/workspaces service mounted/)
+  })
 })
 
 describe('host face', () => {
@@ -212,13 +227,17 @@ describe('host face', () => {
     expect(host.entriesOf('t.host')).toHaveLength(0)
   })
 
-  it('exposes sessions list/current/cell (current riding the list snapshot)', async () => {
+  it('exposes the session list and the atomic current provide projection', async () => {
     const bench = await boot()
     const host = captureHost(bench)
     expect(host.sessions.list.getSnapshot()).toMatchObject({ ids: [] })
-    expect(host.sessions.current.getSnapshot()).toBeUndefined()
-    expect(host.sessions.cell('known')).toMatchObject({ sessionId: 'known' })
-    expect(host.sessions.cell('ghost')).toBeUndefined()
+    expect(host.sessions.provideInfo.getSnapshot()).toMatchObject({ sessionId: undefined })
+  })
+
+  it('exposes the independent Workspace list source', async () => {
+    const bench = await boot()
+    const host = captureHost(bench)
+    expect(host.workspaces.list.getSnapshot()).toEqual({ items: [], phase: 'ready' })
   })
 })
 
@@ -315,6 +334,7 @@ describe('entry-unload cascade', () => {
       renderRoot: (h: SlotRendererHost) => { host = h; return 'rendered' },
     })
     bench.ctx.reflect.provide('sessions', fakeSessions())
+    bench.ctx.reflect.provide('workspaces', fakeWorkspaces())
     // The declarer here is NOT the root occupant: root stays occupied by a
     // separate entry so disposing the declarer only kills its children.
     const disposeRoot = bench.erased.register({ name: 'root' }, C)

packages/client/runtime/tests/wire-events.spec.ts

@@ -0,0 +1,55 @@
+/**
+ * Wire-to-typed-event bridge (web input-triggers cut 1): host/commands-changed
+ * → ctx 'commands/changed'; each established connection generation →
+ * ctx 'connection/reset' (the forced cache-invalidation broadcast).
+ */
+import { Context } from 'cordis'
+import { describe, expect, it } from 'vitest'
+import type { ConnectionHandle, ConnectionSinks } from '@deepseek-ai/dsh-client-connection/client'
+import * as RuntimeClient from '../src/client/index.ts'
+import { FakeApiClient } from './fake-api.ts'
+
+interface Bench {
+  ctx: Context
+  sinks: ConnectionSinks | undefined
+}
+
+async function mount(): Promise<Bench> {
+  const ctx = new Context()
+  const api = new FakeApiClient()
+  const bench: Bench = { ctx, sinks: undefined }
+  const handle: ConnectionHandle = {
+    api,
+    start: (sinks) => {
+      bench.sinks = sinks
+      return { stop: () => {} }
+    },
+  }
+  ctx.reflect.provide('connection', handle)
+  await ctx.plugin(RuntimeClient).await()
+  return bench
+}
+
+describe('wire event bridge', () => {
+  it('broadcasts commands/changed on a host/commands-changed frame, not on other host frames', async () => {
+    const bench = await mount()
+    let changed = 0
+    bench.ctx.on('commands/changed', () => { changed++ })
+    bench.sinks?.onHostEnvelope?.({ rpcId: 'r1' as never, payload: { type: 'host/commands-changed' } })
+    expect(changed).toBe(1)
+    bench.sinks?.onHostEnvelope?.({
+      rpcId: 'r2' as never,
+      payload: { type: 'host/session-status', sessionId: 's1' as never, running: true },
+    })
+    expect(changed).toBe(1)
+  })
+
+  it('broadcasts connection/reset on every established generation (reconnect invalidation)', async () => {
+    const bench = await mount()
+    let resets = 0
+    bench.ctx.on('connection/reset', () => { resets++ })
+    bench.sinks?.onConnected?.()
+    bench.sinks?.onConnected?.() // second generation after a reconnect
+    expect(resets).toBe(2)
+  })
+})

packages/client/runtime/tests/workspaces-service.spec.ts

@@ -0,0 +1,265 @@
+import { Context } from 'cordis'
+import { describe, expect, it } from 'vitest'
+import type { SessionId, WorkspaceId, WorkspaceView } from '@deepseek-ai/dsh-client-connection/client'
+import { SessionsService } from '../src/client/sessions/service.ts'
+import { WorkspaceManager } from '../src/client/workspaces/manager.ts'
+import { WorkspaceCreateError, WorkspacesService } from '../src/client/workspaces/service.ts'
+import { FakeApiClient, deferred, err, ok } from './fake-api.ts'
+
+const sid = (id: string): SessionId => id as SessionId
+const wid = (id: string): WorkspaceId => id as WorkspaceId
+
+function workspace(id: string, sessionIds: SessionId[] = [], createdAt = '2026-01-01T00:00:00.000Z'): WorkspaceView {
+  return {
+    workspaceId: wid(id), path: `/w/${id}`, title: id, sessionIds,
+    createdAt, updatedAt: createdAt,
+  }
+}
+
+describe('WorkspaceManager', () => {
+  it('replays changed frames over hydration and keeps established order on refresh', async () => {
+    const api = new FakeApiClient()
+    const gate = deferred<Awaited<ReturnType<FakeApiClient['onWorkspaceList']>>>()
+    api.onWorkspaceList = () => gate.promise
+    const manager = new WorkspaceManager(api)
+    const hydration = manager.refresh()
+    manager.handleHostEnvelope({
+      rpcId: 'changed' as never,
+      payload: { type: 'host/workspace-changed', workspace: workspace('new') },
+    })
+    gate.resolve(ok({ items: [workspace('old')] as never[] }))
+    await hydration
+    expect(manager.getSnapshot()).toMatchObject({ phase: 'ready', state: 'idle' })
+    expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['new', 'old'])
+
+    api.onWorkspaceList = () => Promise.resolve(ok({
+      items: [workspace('old'), workspace('new')] as never[],
+    }))
+    await manager.refresh()
+    expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['new', 'old'])
+  })
+
+  it('single-flights refreshes and exposes result and transport failures independently of readiness', async () => {
+    const api = new FakeApiClient()
+    const gate = deferred<Awaited<ReturnType<FakeApiClient['onWorkspaceList']>>>()
+    api.onWorkspaceList = () => gate.promise
+    const manager = new WorkspaceManager(api)
+    const first = manager.refresh()
+    const second = manager.refresh()
+    expect(manager.getSnapshot().state).toBe('loading')
+    gate.resolve(ok({ items: [] }))
+    await Promise.all([first, second])
+    expect(api.callsOf('workspace.list')).toHaveLength(1)
+
+    api.onWorkspaceList = () => Promise.resolve(err({ code: 'internal', message: 'down', details: {} }))
+    await manager.refresh()
+    expect(manager.getSnapshot()).toMatchObject({ phase: 'ready', state: 'error', error: { message: 'down' } })
+    api.onWorkspaceList = () => Promise.reject(new Error('wire down'))
+    await manager.refresh()
+    expect(manager.getSnapshot()).toMatchObject({ phase: 'ready', state: 'error', error: { message: 'wire down' } })
+  })
+
+  it('creates by name/path, prepends a new row, and folds failures', async () => {
+    const api = new FakeApiClient()
+    const manager = new WorkspaceManager(api)
+    api.onWorkspaceCreate = payload => Promise.resolve(ok({
+      workspace: workspace('created', [], '2026-02-01T00:00:00.000Z'),
+      created: true,
+      payload,
+    } as never))
+    await expect(manager.create({ name: 'created' })).resolves.toMatchObject({ ok: true })
+    expect(api.callsOf('workspace.create')).toEqual([{ name: 'created' }])
+    expect(manager.getSnapshot().items[0]?.workspaceId).toBe('created')
+
+    api.onWorkspaceCreate = () => Promise.reject(new Error('create transport'))
+    await expect(manager.create({ path: '/w/existing' })).resolves.toMatchObject({
+      ok: false, error: { code: 'internal', message: 'create transport' },
+    })
+  })
+
+  it('replays removal over an in-flight baseline and ignores duplicate or late updates', async () => {
+    const api = new FakeApiClient()
+    const gate = deferred<Awaited<ReturnType<FakeApiClient['onWorkspaceList']>>>()
+    api.onWorkspaceList = () => gate.promise
+    const manager = new WorkspaceManager(api)
+    const hydration = manager.refresh()
+    manager.handleHostEnvelope({
+      rpcId: 'removed' as never,
+      payload: { type: 'host/workspace-removed', workspaceId: wid('gone') },
+    })
+    gate.resolve(ok({ items: [workspace('gone'), workspace('kept')] as never[] }))
+    await hydration
+    expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['kept'])
+
+    manager.handleHostEnvelope({
+      rpcId: 'late-change' as never,
+      payload: { type: 'host/workspace-changed', workspace: workspace('gone') },
+    })
+    manager.handleHostEnvelope({
+      rpcId: 'duplicate-remove' as never,
+      payload: { type: 'host/workspace-removed', workspaceId: wid('gone') },
+    })
+    expect(manager.getSnapshot().items.map(item => item.workspaceId)).toEqual(['kept'])
+  })
+
+  it('removes from the unary delete echo while a refresh is in flight', async () => {
+    const api = new FakeApiClient()
+    api.onWorkspaceList = () => Promise.resolve(ok({ items: [workspace('gone')] as never[] }))
+    const manager = new WorkspaceManager(api)
+    await manager.refresh()
+    const gate = deferred<Awaited<ReturnType<FakeApiClient['onWorkspaceList']>>>()
+    api.onWorkspaceList = () => gate.promise
+    const refresh = manager.refresh()
+
+    await expect(manager.delete(wid('gone'))).resolves.toMatchObject({ ok: true })
+    expect(api.callsOf('workspace.delete')).toEqual([{ workspaceId: 'gone' }])
+    expect(manager.getSnapshot().items).toEqual([])
+    gate.resolve(ok({ items: [workspace('gone')] as never[] }))
+    await refresh
+    expect(manager.getSnapshot().items).toEqual([])
+  })
+})
+
+describe('WorkspacesService', () => {
+  it('feeds readiness and recent-Workspace targeting without changing Host order', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    api.onWorkspaceList = () => Promise.resolve(ok({
+      items: [
+        workspace('stable-first', [], '2026-01-03T00:00:00.000Z'),
+        workspace('active', [sid('s-active')], '2026-01-01T00:00:00.000Z'),
+      ] as never[],
+    }))
+    await workspaces.refresh()
+    await Promise.resolve()
+    expect(workspaces.list.getSnapshot()).toMatchObject({ baselinesReady: false, recentWorkspaceId: undefined })
+
+    api.onList = () => Promise.resolve(ok({
+      items: [{ sessionId: sid('s-active'), updatedAt: Date.parse('2026-02-01'), running: false, blank: false }] as never[],
+    }))
+    await sessions.refresh()
+    await Promise.resolve()
+    await Promise.resolve()
+    expect(workspaces.list.getSnapshot()).toMatchObject({
+      baselinesReady: true,
+      recentWorkspaceId: 'active',
+    })
+    expect(workspaces.list.getSnapshot().items.map(item => item.workspaceId)).toEqual(['stable-first', 'active'])
+  })
+
+  it('connectWorkspace reuses the workspace-matched blank session and creates otherwise', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    api.onWorkspaceList = () => Promise.resolve(ok({
+      items: [workspace('alpha'), workspace('beta')] as never[],
+    }))
+    api.onList = () => Promise.resolve(ok({
+      items: [
+        // Blank session already parked in alpha (cwd == workspace path canon).
+        { sessionId: sid('s-blank'), updatedAt: 2, running: false, blank: true, cwd: '/w/alpha' },
+        // Non-blank sibling in beta must never be reused.
+        { sessionId: sid('s-active'), updatedAt: 3, running: false, blank: false, cwd: '/w/beta' },
+      ] as never[],
+    }))
+    await Promise.all([workspaces.refresh(), sessions.refresh()])
+    await Promise.resolve()
+
+    // Hit: same workspace → the parked blank session comes back, no create RPC.
+    await expect(workspaces.connectWorkspace(wid('alpha'))).resolves.toBe('s-blank')
+    expect(api.callsOf('session.create')).toEqual([])
+    // Resolution guarantee: the id is binding-resolvable synchronously.
+    expect(sessions.binding(sid('s-blank'))).toBeDefined()
+
+    // Miss: beta has only a non-blank session → host create with workspaceId.
+    api.onCreate = () => Promise.resolve(ok({ sessionId: sid('s-fresh') }))
+    await expect(workspaces.connectWorkspace(wid('beta'))).resolves.toBe('s-fresh')
+    expect(api.callsOf('session.create')).toEqual([{ workspaceId: 'beta' }])
+    // Same guarantee on the create arm (draft hand-off writes the machine pre-open).
+    expect(sessions.binding(sid('s-fresh'))).toBeDefined()
+
+    // Unknown workspace fails loud instead of silently creating in nowhere.
+    await expect(workspaces.connectWorkspace(wid('ghost'))).rejects.toThrow(/unknown workspace ghost/)
+  })
+
+  it('a rejected first prompt keeps the blank session eligible for connectWorkspace reuse', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    api.onWorkspaceList = () => Promise.resolve(ok({ items: [workspace('alpha')] as never[] }))
+    api.onList = () => Promise.resolve(ok({
+      items: [{ sessionId: sid('s-blank'), updatedAt: 2, running: false, blank: true, cwd: '/w/alpha' }] as never[],
+    }))
+    await Promise.all([workspaces.refresh(), sessions.refresh()])
+    await Promise.resolve()
+    const session = sessions.binding(sid('s-blank'))!.session
+    api.onPrompt = () => Promise.resolve(err({ code: 'internal', message: 'agent busy', details: {} }) as never)
+    await session.prompt([{ type: 'text', text: 'hi' }], 'queue')
+    await Promise.resolve()
+    // Failure leaves blank intact, so the same session is still the reuse hit.
+    await expect(workspaces.connectWorkspace(wid('alpha'))).resolves.toBe('s-blank')
+    expect(api.callsOf('session.create')).toEqual([])
+  })
+
+  it('returns created Workspaces and preserves Host business errors', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    api.onWorkspaceCreate = () => Promise.resolve(ok({
+      workspace: { ...workspace('picked'), path: '/w/alpha', title: 'alpha' }, created: true,
+    }))
+    await expect(workspaces.create({ path: '/w/alpha' })).resolves.toMatchObject({ workspaceId: 'picked' })
+    expect(workspaces.list.getSnapshot().items[0]).toMatchObject({ path: '/w/alpha', title: 'alpha' })
+    expect(api.callsOf('workspace.create')).toEqual([{ path: '/w/alpha' }])
+    api.onWorkspaceCreate = () => Promise.resolve(err({
+      code: 'workspace-invalid-path', message: 'missing', details: { path: '/missing' },
+    }))
+    const rejected = workspaces.create({ path: '/missing' })
+    await expect(rejected).rejects.toThrow(/workspace-invalid-path: missing/)
+    await expect(rejected).rejects.toBeInstanceOf(WorkspaceCreateError)
+  })
+
+  it('passes native directory selection and cancellation through without local state', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    api.onPickDirectory = () => Promise.resolve(ok({ path: '/w/alpha' }))
+    await expect(workspaces.pickDirectory()).resolves.toBe('/w/alpha')
+    api.onPickDirectory = () => Promise.resolve(ok({ path: null }))
+    await expect(workspaces.pickDirectory()).resolves.toBeNull()
+    expect(api.callsOf('host.pickDirectory')).toEqual([{}, {}])
+  })
+
+  it('opens a filesystem path through the host without local state', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    await expect(workspaces.openPath('/w/alpha/a.ts')).resolves.toBeUndefined()
+    expect(api.callsOf('host.openPath')).toEqual([{ path: '/w/alpha/a.ts' }])
+    api.onOpenPath = () => Promise.resolve(err({ code: 'internal', message: 'boom', details: {} }))
+    await expect(workspaces.openPath('/missing')).rejects.toThrow(/path open failed/)
+  })
+
+  it('deletes a Workspace or preserves it when the Host rejects deletion', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    api.onWorkspaceList = () => Promise.resolve(ok({ items: [workspace('alpha')] as never[] }))
+    await workspaces.refresh()
+    await expect(workspaces.delete(wid('alpha'))).resolves.toBeUndefined()
+    expect(workspaces.list.getSnapshot().items).toEqual([])
+
+    api.onWorkspaceDelete = () => Promise.resolve(err({
+      code: 'workspace-not-found', message: 'gone', details: { workspaceId: 'ghost' },
+    }))
+    await expect(workspaces.delete(wid('ghost'))).rejects.toThrow(/workspace-not-found: gone/)
+  })
+})

packages/client/runtime/tsconfig.json

@@ -23,6 +23,15 @@
     {
       "path": "../../host/apiproxy"
     },
+    {
+      "path": "../../ui/commands"
+    },
+    {
+      "path": "../../session-projection/session-projection"
+    },
+    {
+      "path": "../../session-title/session-title"
+    },
     {
       "path": "../../llm/llm"
     },