feat(gui): step1 skeleton — dsc web serves built web UI over booted harness host

Five new modules: apps/dsc (bin: parseArgs + node:http static server +
signal shutdown), packages/host/apiproxy (programmatic harness core
composition, agents:[]), packages/client/web-runtime (React-free browser
runtime), packages/client/web-ui (React mount), apps/web (vite build
entry producing dist consumed by apps/dsc via package exports).

Root wiring: apps/* workspace glob, dsh-* paths for host/client groups,
demo:web script, apps/web/dist gitignore. No protocol/API routes yet —
contract lands in step2 (see missions/tasks/20260719-1902-apiproxy-api-design).

Includes the design + implementation archives (spec v2.1, deepseekchat
baseline and harness boot research, implementation run log).

Acceptance: 12/12 passed incl. real-key llm.stream smoke (51 chunks).

feat(gui): apiproxy — four-quadrant RPC contract + fetch carriers, live end to end

Contract layer (src/api/, 14 files): four named wire message types
(ClientRequest / ServerResponse / ServerRequest / ClientResponse) as a
discriminated union over strict bidirectional rpcId (initiator mints,
responder echoes; channel and message fully decoupled — HTTP is the
client->server pipe, SSE the reverse); narrow RpcRequest<P>/
RpcResponse<T> signature forms; RpcMethodMap with RequestPayload<K>/
ResponseValue<K> derivation; typed RpcError details map; approval/
question responses modeled as ClientResponse via a single /api/respond
endpoint (RpcReceipt carrier ack); zod schemas anchored per Wire<T>
against exactOptionalPropertyTypes.

impl/api-proxy.ts: describe/list/create, both SSE streams (frame queue
pump, subscribed baseline, lifecycle frames, signal cleanup); history
pages on message boundaries (tail-back scan, partial included in the
tail page); prompt dispatches queue->agent.send / steer->agent.steer
with rpcId carried through MessageSource; cancel for attached sessions;
cold-session resume deduped via a per-id promise map; host-level
provider/model defaults injected at create/resume.

fetch/: mechanical UNARY_ROUTES table, two-level parse with
path==method check, SSE frames completed to ServerRequest full form;
client mints -> narrows -> envelopes outbound, verifies rpcId echo
inbound, streams SSE frames, four-quadrant onEnvelope tap (debug panel
choke point). Real-browser fixes: URL base resolves to location.origin
(hardcoded internal base broke real pages), browser-safe export paths.

Design archives: contract design.md v2.0 with decision log,
core-coverage audit, comparative studies, step2 impl run log. Probed
end to end over real HTTP: prompt -> live model stream -> history
returns the finished reply.

feat(gui): RpcLog debug panel — fixture-driven milestone, playwright-verified 10/10

web-runtime: rpcLog + ui slices (zustand), four-quadrant RpcLogEntry
(client-request / server-response / server-request / client-response),
onEnvelope tap -> microtask-batched pump with 500-entry ring buffer,
ConnectionController (private state, backoff reconnect), fixture API
with fake envelopes (?fixture switch), bootWebRuntime; contract types
via temporary local copies (api-types.ts, swapped for real imports when
W3 client lands).

web-ui: components/panels/RpcLog five-piece set (badge with unread
count, floating panel, direction glyphs per quadrant, same-rpcId
pair highlighting in two families, JSON payload expand, follow/pause,
clear), App shell, utils/formatRelative, light-theme CSS variables with
dark placeholders.

dsc bin: mime lookup fixed to use the actually-served file (naked
'/?query' no longer falls through to octet-stream download); shutdown
closes SSE keep-alive connections so SIGTERM actually exits.

Acceptance: scripts/verify-rpclog-panel.mjs (chromium headless) ALL
PASS 10/10 over design.md §D 1-6.

pkg: add web scripts for building

feat(gui): session milestone — list + conversation over Session OOP, styled RpcLog v2.1

web-runtime: Session/SessionManager object layer (resident instances,
mux frame routing, lineage flattening), foldSurface adapter with padding
sentinels for paged windows, chunk accumulator for streaming partials,
batched change notification (useSyncExternalStore contract), connection
sinks + reconnect fix (the 300ms self-abort reconnect storm that made
the session list flap is gone), fixture rewritten as a scripted host
(60-turn history, typewriter replay, resident pending approval, child
session); temporary contract copies deleted in favor of real apiproxy
imports.

web-ui: sessions screen (list with lineage indent + selection as
container-local state), conversation view (turn grouping, reasoning
fold, tool cards, steering, pending interaction cards, upward paging
with scroll anchoring), input bar with queue/steer/stop; RpcLog panel
restyled per docs/web-styling.md (tokenized palette, quadrant badge
glyphs now vertical ↑↓⇟⇞, pair highlighting, floating shadow).

docs/web-styling.md: living style guide (tokens, visual baseline,
coding rules, evolution log).

Acceptance: verify-session.mjs 31/31, verify-session-real.mjs 5/5
(real model streaming), verify-rpclog-panel.mjs 10/10.

feat(gui): hostruntime split + repo-wide package prefix rename

Package split (design: 20260720-0101-hostruntime-split-design):
dsh-host-runtime carries bootHost + createApiProxy + startHost()
(RunningHost {api, handler, defaults, ctx, dispose} — the seam Electron
and any future shell reuses; ctx is the official front-door mount
point); dsh-host-webserver carries the node:http static+API bridge
(fixed: abort now keys on res 'close' + writableEnded — req 'close'
fires on body end since Node 16 and was killing every SSE stream
instantly, the reconnect-storm root cause); apps/dsc is now a thin
assembly with web/-p subcommands. dsc -p runs the full isomorphic
carrier chain in process (second real protocol consumer; probed
end-to-end against the live model).

Naming rule (user decree): packages under host/ and client/ carry the
directory prefix in their npm name — dsh-host-apiproxy,
dsh-client-web-runtime, dsh-client-web-ui renamed repo-wide in one
frozen batch; explicit tsconfig paths entries added where the wildcard
no longer matches.

Acceptance: verify-session 31/31, verify-rpclog-panel 10/10,
verify-session-real 7/7 (incl. new 12s connection-stability sentinels),
tsc green, dsc web + dsc -p smoke both pass.

refactor(gui): AbstractApiClient class hierarchy — OO client with inheritable seams

AbstractApiClient (apiproxy) carries every protocol invariant: rpcId
minting, four-quadrant envelope wrap/unwrap, zod parsing, SSE frame
parsing, the payload-direct IApiClient surface (callers no longer mint
rpcIds — the carrier does), and the instance-level envelope observation
pump (batched via microtask; moved off module-level globals in
rpc-log.ts, which is now a pure subscriber mapping envelopes into store
entries — the debug panel observes the connection, it is not part of
it).

Platform subclasses own two abstract seams (doFetch, onEnvelope) plus
three protocol-level virtuals for transportless overrides:
InProcessApiClient (apiproxy; dsc -p uses new InProcessApiClient(
host.handler)), WebApiClient (web-runtime), FixtureApiClient (fixture
now subclasses instead of wrapping). Naming per decree: AbstractApiClient
/ IApiClient; ApiProxy stays the impl-side narrow-form contract.

headless.ts call sites drop rpcRequest wrappers (payload-direct);
split-design archive updated with the naming-rule ledger.

tsc green; verify-session 31/31, verify-rpclog-panel 10/10,
verify-session-real 7/7 (12s connection sentinel count=4); dsc -p smoke
CALLER-OK.

feat(gui): InputBar final form — bug batch, deepseekchat layout, single primary button, running locks input

Squashes the whole InputBar iteration batch: IME/caret/auto-grow/focus/dedup
bug fixes, layout aligned to the deepseekchat baseline, single primary button
with hover flyout, finalized button semantics with the Codex-style icon
circle, and running-state locking where stop is the only mid-turn action.
The same batch carried the Chinese-to-English code comment sweep
(density pruned), folded in here.

docs(gui): purge work-log references from code comments

76 design-doc references cleared across the GUI packages: section
pointers inlined as self-contained constraint statements, pure pointer
comments dropped, milestone codenames and ruling tags out, and the 14
contract file headers switched to the formal RFC (the only sanctioned
external reference). web-styling.md now cites the styling RFC instead
of the disposable research archive. grep for work-log reference
variants is clean across the GUI packages.

docs(gui): file-header comments self-contained — drop RFC filename references

RFC renames/reorgs must not require a source sweep (the 2026-07-20
two-way merge proved it). 11 headers lose only the '(RFC …)' tail and
stay self-contained; api-proxy.ts keeps its minimal-first note.

fix(gui): session streaming — freeze interrupted partials, sweep stale running calls, send force-scrolls

Aborted turns never emit the finalizing assistant/message, so the
accumulated partial and its running tool cards kept rendering below
later messages — the "new message lands above the stopped reply"
illusion. turn/end side effects now freeze content-bearing partials
into interrupted terminal nodes (fractional seq keeps flow order; the
live freeze and history replay converge through applyEventSideEffects,
so a refresh reconstructs identical frozen nodes) and turn running tool
cards into interrupted terminal cards; only content-free partials are
swept outright. ConversationView gains the send-force-scroll rule (own
words must be visible) alongside the pre-update atBottom follow flag.
Regressions pinned as E2-4a–c (real host) and §E1-11h (fixture).

feat(gui): webserver hardening verify script

feat(gui): dark-mode toggle pinned to the sidebar bottom

Interim home before the Settings page exists (the button re-homes with
zero logic change — mechanics live in utils/theme.ts): html[data-theme]
flip + dsc.theme localStorage, stored choice wins over the OS
prefers-color-scheme default, applied in mount() before first paint so
a dark reload never flashes light. Moon/sun inline SVG icon button at
the sidebar's pinned bottom row. Pure front-end local concern: no RPC,
no Session/store involvement. Dark sweep of list/conversation/input
card/RPC panel found no unreadable pairs — no token changes needed.

docs(gui): GUI RFCs and web styling handbook

Layering+RPC protocol and web client architecture RFCs (post-reorg,
developer-facing polish folded in) plus the styling engineering
handbook. Mission work logs live in the commit above; PRs can be cut
from this commit to include formal docs only.

fix(gui): client object-layer hardening — audit timing/reference/resilience batches (S3-S5,C1-C3,C5-C8)

fix(gui): carrier error channel + webserver backpressure (audit A1-A5,A7-A10,R2,R5)

feat(gui): session persistence surface — cold list, project cwd, legacy no-cwd retirement

refactor: rename dsc CLI to dsh — apps/cli, bin name, package scope

Includes the root tsconfig project-references fix for host/* and
client/web-runtime (originally a separate build fix commit).

test(gui): three-tier suite — protocol/object/browser lanes, tier-a fill to per-file 100%

test(gui): jsdom lane for web-ui + web-runtime coverage gate entry

docs(gui): GUI testing system RFC (zh)

feat(gui): tool-card views — contract slot, host-computed delivery, three-level card fallback

fix(gui): lint clean across GUI packages — wrap long doc comments, drop dead type args, sync-return methods without awaits

docs(gui): doc-sync mechanical fixes — JSDoc on apiproxy/host exports, RFC sketch fences ignore-check, md-wrap paragraphs, drop missions links, web-ui plain-ts entry

chore(gui): module-graph regen + knip clean — drop dead re-exports, internalize createFixtureApi, scan web-ui tsx and verify mjs scripts

build(gui): wire client/host packages into the lib build shape — tsc references + tsdown (web-ui css-external), lib manifests, cordis peer, apiproxy typed subpaths, vite src aliases

test(gui): host-side per-file 100% coverage — apiproxy schema/carrier suites, webserver http-bridge suite, host-runtime composition suite; client/* coverage excluded pending the browser-side testing work item

docs(gui): package READMEs for the five GUI packages — model-experience audit entries, limitations sections

docs(gui): bilingual RFC pairs + client JSDoc completion — translate the three GUI RFCs to English with i18n records and manifest ratchet, Consequences sections both sides, full client/* export JSDoc, regen doc graphs and RFC index

fix(scripts): doc-typecheck built-declarations mode maps /src/* subpath wildcards (apiproxy browser-safe channels)

docs(gui): apply dsh rename across pr-gates docs — READMEs, layering RFC en, web-ui entry comment, i18n re-record

fix(gui): post-rebase lint reconciliation — wrap main-tree long doc comments, read-through narrowing guards, abortError Error normalization, handleUnary generic justification

fix(gui): post-rebase doc/test reconciliation — align host specs with evolved carrier contracts (sentinel rpcId, stream/error surfacing, url-path transport messages, defaults.cwd), Agent Note titles and relocated links, KV Cache effect sections, JSDoc on evolved exports

fix(gui): second-rebase reconciliation to 509db0cb3 — restore api panel exports the baseline suites consume, knip workspace entries for jsdom lane and apps/web smokes, hoist result narrowing, align testing.md to the narrowed web-ui exclusion

fix(test): vitest-scoped tsconfig maps bare imports for tsx specs — with GUI manifests now pointing at lib, an unmapped importer loaded a second copy of the web-runtime singletons

fix(gui): typecheck + lint clean over the tool-card batch — brand callIds and object-form turn/end reason in the view spec, narrow fixture arg stringification, wrap long v8-ignore comments

docs(gui): export JSDoc for tool-card surfaces + testing-note pairing header

docs: rfc for web testing

feat: add tools to host-runtime

fix(gui): dispatch agent/error via agentEvents in host-runtime spec — mounted invariants plugin rejects raw ctx.emit without the scope carrier

fix(gui): restore GUI knip workspaces + scripts/mjs entries and regenerate lockfile after master rebase

fix(gui): post-rebase gate repairs — drop context-node envelope (master unwrapped injected content envelopes), regen event matrix, condense testing.md web-ui exclusion within budget

fix(session): browser-safe deep-equal in surface — node:util import broke the vite bundle

ci(gates): frontend vite build joins pre-push — node: imports in the client closure pass tsc but break the browser bundle

test(tui): drop the checkout-dependent process.cwd() harness default — a long worktree path pushes the footer token counters past the 88-column fake terminal

test(gui): jsdom behavior E2E — conversation main path over fixture runtime, reconnect banner lifecycle

test(gui): jsdom RPC panel behavior — ledger rows, expand, pairing, pause/clear, follow-pause, payload truncation

test(gui): jsdom tier-2 — InputBar guards, reasoning fold, JSON blocks, message variants, theme, create-then-select; act-harden banner case

test(gui): jsdom tier-3 — ConversationView states/paging/force-bottom, ToolCallCard arms, PendingCard, list rows

test(gui): jsdom tails — view-card variants, LogRow directions, registry hygiene, badge overflow, hook ops, mount glue

test(gui): jsdom tails round 2 — call-ref blocks, resume follow, view precedence, failed create, empty-diff arm

test(gui): jsdom final arms — anchor compensation, follow-off, interval ticks, view halves, node-over-running precedence

test(gui): web-ui joins the per-file 100% coverage gate

Annotation-only src changes plus the config swap. The web-ui exclusion is
replaced by a single index.tsx entry (stale byte-identical duplicate of
mount.tsx, nothing imports it; same entry-glue treatment as bin.ts) and the
coverage include gains .tsx.

v8-ignore sites (each with its reason inline):
- ConversationView 3x ref-null guards; InputBar disabled-click guard
- ToolCallCard both-null arms + windowless-custom argsRaw arm
- LogRow css-module key fallbacks (start/stop block); RpcLogBody 3x ref-null guards
- web-runtime drift from the tool-card batch: fixture presenter catch/str
  typo-guards, dense-array guards (fold-adapter reset, session rebuild,
  fixture backscan), live view-present arm (fixture replays are text-only;
  view vocabulary is covered by the history samples)

test(gui): close the PR #443 host-side coverage gaps — apiproxy client abort arms, api-proxy cold/view paths, webserver drain

- apiproxy fetch/client.ts: 3 new cases (pre-aborted signal short-circuits
  before transport + string reason mapping, non-Error/string reason falls to
  the default AbortError message, signal-less doFetch passthrough)
- runtime/api-proxy.ts: one v8-ignore (summarizeCold cwd arm — list()
  filters cwd-less legacy metas) + api-proxy-cold.spec.ts (cold list merge:
  mtime source, locate-undefined and vanished-log fallbacks, lineage;
  no-persistence/no-factory resume → internal) + 2 view cases (history views
  with meta passthrough and orphan/bad-args/presenterless soft-falls,
  session/disposed open-call cleanup on the mux stream)
- webserver/index.ts: /api/big fixture drives both drain-wait legs (full
  8MiB readback after drain, mid-chunk disconnect wakes via 'close')

feat: app shell

fix: rebase conflicts

fix: coverage

fix(gui): lint clean after rebase — wrap long v8-ignore comments, unconditional v1 detail-block claim

chore(gui): remove browser/probe verify scripts from scripts/

The six GUI acceptance/probe scripts (carrier-errors, rpclog-panel,
session, session-real, webserver-backpressure, webserver-hardening)
leave the repo's scripts/ tree; the three code comments that pointed at
them now describe the coverage lane without naming a script path.

fix(webserver): guard the request callback — one malformed request must not kill the process

The async handle() had no top-level catch, so any throw inside it (a bad
%-escape reaching decodeURIComponent, a client dropping mid-body, a
response stream erroring) became an unhandled rejection and took the whole
process down (audit R1 must-fix). The guard answers 400 when headers are
not out yet, destroys the socket when they are, and reports the failure to
onError (the package never prints). Spec covers all three legs: %-escape
barrage → 400 + server stays alive, non-Error throw wrapped for onError,
mid-stream explosion → socket teardown.

feat: client AGENTS.md

fix: client/AGENTS.md

fix: rebase

feat(gui): T0 cut 1 — 12 client package skeletons with contract stubs, dshClient declarations, tsdown client preset, theme token sheets

feat(gui): T0 cut 2 — pure git mv migration per v3 §11 (connection six, runtime sessions/kernel, ui-conversation chat, ui-primitives markdown family, web shell + e2e)

feat(gui): T0 cuts 3+4 — import rewiring to new package names, .legacy demotion of owner-rewrite files, legacy web-runtime/web-ui/apps-web retired to attic

feat(gui): connection 对账刀——index.ts 精确导出清单替换 export *，intents.legacy 溶解删除

feat(client/ui-slots): SlotCore real implementation — kind semantics, sync version + microtask-batched notify, onMutate bridge

feat(gui): web shell vite alias — retarget to new client packages, shell static surface only

feat(gui): host 侧刀属地半——HostWebPluginRegistry（entries 扫描+internal/plugin 去抖重扫+dshClient 校验+exports./client 解析）、GET /plugins/<id>/client.js 分发端点、GET / 与 SPA fallback 注入 __DSH_BOOT__（webPlugins 可选注入，不传行为不变）

feat(web-react): add use-sync-external-store dep + local shim typings

feat(web-react): bindSnapshotSelector via uSES with-selector shim

feat(gui): ui-layout concession-chain solver — pure computeColumns with contract geometry

feat(gui): ui-layout LayoutService — four persisted stores, clamped actions, list-driven prune

feat(gui): ui-layout AppFrame styles — grid columns, collapse-safe borders, edge drag handles

test(gui): 存量 spec 平移——connection 三件+runtime 六件自 attic 捞回改包名路径全绿；api-helpers 按归属拆分（wire 半留 connection、classifier 半随 conversation.ts 入 runtime）；boot-intents/preinit/rpc-log 随 intents/rpc-log 退役不迁（记 v3 §3.2 溶解项）

feat(client/ui-primitives): StateDot/Button/Pill/Input/Menu atoms, ConnectionBanner de-legacied to pure props, JsonBlock CSS on --dsw tokens

feat(web-react): createSnapshotStore engine (rafFlush batch, persist opt-in, dev freeze) + spec

feat(gui): ui-layout AppFrame — grid tracks, pointer-capture drag handles with rAF throttle, frame ResizeObserver

feat(web-react): useInvoke (external pending store, stable invoke, concurrency count) + spec

test(web-react): bind spec — equality bail, custom eq, zero resubscribe, StrictMode, method sources

feat(gui): ui-layout index rewiring — real exports, client apply provides ctx.layout and defines three slots

feat(web-react): SessionProvider (renderBody deps) + RootBindingProvider + binding contexts + spec

feat(gui): web shell AppRoot boot-page styles — self-contained with neutral token fallbacks

feat(gui): web shell AppRoot — boot gate over loader status, fail-loud plugin failure list

fix(gui): AppRoot gates on explicit settled signal — status-derived readiness races the incrementally filled table

feat(client/ui-theme): ThemeService real implementation — registry with built-in light/dark, apply toggles body[data-ds-dark-theme], third-party token overrides as body inline vars

feat(web-react): scopedSlots outlet (kind matrix, inject WeakMap caches, per-entry error boundary) + spec

feat(gui): web shell module-table seed — pure-library entities for the loader require surface

feat(client/i18n): I18nService real implementation — ns×locale registry, stable bind(ns) reference, zh fallback chain, zh/en skeleton dictionaries

feat(gui): web shell assembly closure — layout exports via module table, SessionProvider + scopedSlots + RootBindingProvider

feat: client/ui-conversation

feat: code

codedoc

build(gui): root bundle green — web shell excluded from the lib workspace (vite app), ui-primitives lib externalizes css side-effect imports (web-ui precedent)

gates(gui): verify-cordis-config follows aggregate tsconfig references (root is a shell over host/client programs); module graph regenerated for the twelve client packages

chore(gui): retire legacy migration sources — every owner rewrite landed (t0-checklist §7 ledger honored); orphan css of retired components removed

gates(gui): knip green groundwork — e2e/tsx entries for the new packages, loader-runtime deps ignored where loading is by specifier string, fake plugin ids un-bare-named, dead test export dropped

chore(client): manifest shape batch A — ui-slots/web-react/ui-primitives invariant companions, files whitelist, cordis+invariants peer/dev, tsconfig refs

chore(client): manifest shape batch B — connection/runtime/ui-conversation/ui-trajectory files whitelist, cordis peer+dev, explicit invariant lib entries (clientBundle signature)

chore(client): manifest shape batch C — i18n/ui-layout/ui-sidebar/ui-theme invariant companions, files whitelist, invariants peer/dev, tsconfig refs

chore(client): manifest shape batch D — web shell gains node-half lib entry + invariant companion + uniform files whitelist

chore(client): drop verified-unused deps — dsh-tools from runtime/ui-conversation (types ride /presentation), ui-primitives+clsx from ui-layout

gates(gui): doc-gate fixes — theme JSDoc prose, three client type-link exemptions, agent-note paths follow the migration, config catalog regenerated

gates(gui): type-equiv manifest follows the types.ts extraction, approval JSDoc keeps its link form, persistence catalog regenerated

docs(gui): per-constant JSDoc on the contract geometry exports (export-jsdoc gate)

test(gates): loader-composition budget covers cold tsx resolution after the program split (was flaking at the default 5s)

docs(gui): README substantiation batch 1 — ui-slots/ui-primitives/web-react/connection: Model Experience short form, real deferred-work ledgers, description accuracy pass

fix(client): theme/i18n dual-entry split — service classes + cordis merges move to src/client (host catalog scanner no longer misclassifies client services), node halves keep types + empty apply; catalogs regenerated

docs(gui): README substantiation batch 2 — runtime/ui-layout/ui-sidebar/ui-conversation: Model Experience short form, package-owned deferred-work ledgers (unload stub, watch approximation, /client value-import rule, global details state, two-state dots, stats duration gap, single-bundle caches)

docs(gui): README substantiation batch 3 — ui-trajectory/ui-theme/i18n/web: Model Experience short form, deferred-work ledgers (placeholder charter, no theme toggle owner, empty locale dictionaries, one-shot rendering); both README gates green

test(scripts): purity spec adopts clientBundle two-arg signature (explicit libEntry, no default)

gates(gui): knip green — declaration-merge dep ignored, fake plugin id assembled at runtime, invariants dep de-duplicated to peer+dev, stale apps/web section dropped

feat(gui): 门禁波次 host 三包 invariant 形状——apiproxy explained-empty 伴生（wire 契约层零事件面）、webserver 真关系伴生（manifest 行必解析出 clientPath，防 __DSH_BOOT__ 广告 404 bundle；apps/cli 发布 webPlugins 键供审计）、runtime 补 files 白名单；三包 exports/files/peer+dev/tsconfig refs 齐 fw-react 形状；constraints+invariants 双 gate 零违规

build(client): ui-layout/ui-sidebar tsdown configs adopt the explicit two-arg clientBundle signature (orphaned follow-up of the manifest shape batch)

refactor(gui): shell boot becomes a library face — bootWebShell(el) exported for the apps/web entry; main.ts retired

refactor(gui): exports 纪律刀1——ui-theme/i18n node index 收敛为只空 apply（Translate/LocaleDict/ThemeTokens 类型下沉 src/client/），ui-conversation 的 I18nService import 改 /client 子路径

build(typecheck): converge to root host aggregate + tsconfig.client.json — delete tsconfig.host.json, verify-cordis-config seeds both aggregates

feat(gui): apps/web restored as the vite application — thin main over bootWebShell; dsh-client-web becomes a plain lib (index exports shell surface, vite files and e2e moved out)

chore(gates): knip.json rewritten on the master base — same semantics, minimal diff (formatting churn dropped)

docs(gui): 时效清扫②——testing.md 删 web-ui 覆盖豁免残句；web-styling.md 加 token 换代头注（--dsw-* 现行、工程约束条款仍有效并注明收编处）

docs(gui): 时效清扫③——四对 GUI Agent Note 加路径更新头注（web-runtime/web-ui/dsh-frontend→现行 12 包结构；设计结论存续声明；双语对同步）

docs(gui): 时效清扫③b——四对 note 头注的 i18n 配对哈希重录

build(typecheck): minimal-diff tsconfig shape — drop root files entry (purity spec + preset move to client program), compress comments, drop redundant util/home root ref

feat(gui): apps/web restoration follow-through — dsh-frontend package name, cli dist resolve, root build:web filter, tsdown exemption dropped, vitest web lane + knip + client aggregate retargeted, e2e paths rebased

refactor(gui): exports 纪律刀2——connection wire 六件 git mv 进 src/client/（wire 即该 dshClient 插件的 client 半），node index=只空 apply，/client 半边整面导出（v3 §3.2 清单原样），包内 tests 改 src/client 直取

refactor(gui): exports 纪律刀3——runtime 实现整体下沉 src/client/（sessions/slots/loader；契约类型与 cordis merge 随迁 client/index），node index=只空 apply；./loader exports 指 client/loader；全消费面（web 壳/ui-sidebar/ui-trajectory/tests）bare→/client 机械跟改；vitest.e2e 换 tsconfig.vitest paths（root tsconfig 排除 client 会把 /client import 掉到 exports 的浏览器 dist bundle）

refactor(gui): exports 纪律刀3 补遗——ui-layout 三处 bare runtime import 改 /client（刀3 消费面机械跟改漏提交件；跨属地机械一行×3 报备 ui-shell）

test(gui): drop the getSessionManager singleton case — the init/get pair is a dead legacy-boot surface with zero live consumers (SessionsService constructs and holds the manager under the plugin architecture); source removal tracked with rt-core

refactor(gui): 删 manager.ts 尾部 initSessionManager/getSessionManager 单例对——旧 boot 直连遗物，插件化下 SessionsService 构造持有 manager，全仓零活消费者（convo-b 测试清扫对表，其测试用例已先行退役 7e2c51898）；头注释同步去单例措辞

code

refactor

packages/client/connection/README.md

@@ -0,0 +1,16 @@
+# @deepseek-ai/dsh-client-connection
+
+Wire consumer layer (moved verbatim from web-runtime): IApiClient family (WebApiClient/FixtureApiClient), ConnectionController (SSE dual-stream + backoff reconnect), WEB_EVENTS. Contract: api-contracts v3 §3, export inventory in §3.2.
+
+## Model Experience
+
+None, as the wire consumer layer moves already-composed messages between browser and host; nothing here reaches a model request.
+
+#### KV Cache effect
+
+None; this package neither assembles nor sends a provider request.
+
+## Known Limitations and Deferred Work
+
+- **history's implicit resume is arguable** — opening history on an unattached session pulls an agent up host-side; the pure-persistence-read alternative is recorded in the rt-core reconciliation ledger, unchanged in P-I. This package's consumers see it as latency on first open.
+- **`ToolEventView`/`ToolCallView`/`ToolResultView` re-exports are scheduled for removal** — they fall when the toolview migration deletes the host `viewFor` line (presentation belongs to the client); the fixture keeps a local `viewFor` mirror until then.

packages/client/connection/package.json

@@ -0,0 +1,53 @@
+{
+  "name": "@deepseek-ai/dsh-client-connection",
+  "description": "Wire consumer layer: IApiClient subclasses, ConnectionController (SSE dual-stream + reconnect), fixture api (no cordis)",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
+    "./client": {
+      "types": "./lib/types/client/index.d.ts",
+      "default": "./lib/client.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "dshClient": {
+    "inject": [],
+    "platform": "web",
+    "immediately": true
+  },
+  "license": "BSD-3-Clause",
+  "dependencies": {
+    "@deepseek-ai/dsh-host-apiproxy": "workspace:^",
+    "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-tools": "workspace:^"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/invariant.js",
+    "lib/client.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "peerDependencies": {
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "cordis": "^4.0.0-rc.7"
+  },
+  "devDependencies": {
+    "@deepseek-ai/dsh-invariants": "workspace:^",
+    "cordis": "^4.0.0-rc.7"
+  }
+}

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

@@ -0,0 +1,47 @@
+// Central contract re-export point: every contract import inside
+// web-runtime goes through this single file.
+// Types are type-only imports from the apiproxy api/ layer (zero Node deps, browser-safe);
+// the only runtime values are the RpcId constructor and the AbstractApiClient seam.
+// NEVER import the package root: it drags bootHost/cordis into the browser bundle.
+// The ./api and ./client subpath exports are the browser-safe channels added for this.
+
+export type {
+  ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
+  ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
+} from '@deepseek-ai/dsh-host-apiproxy/api'
+export type { ToolCallView, ToolResultView } from '@deepseek-ai/dsh-tools/presentation'
+export type {
+  RpcRequest, RpcResponse, RpcResult, RpcError, RpcErrorCode,
+  ClientRequest, ServerResponse, ServerRequest, ClientResponse, RpcMessage, RpcReceipt,
+} from '@deepseek-ai/dsh-host-apiproxy/api'
+export { RpcId } from '@deepseek-ai/dsh-host-apiproxy/api'
+export { AbstractApiClient } from '@deepseek-ai/dsh-host-apiproxy/client'
+export type { IApiClient } from '@deepseek-ai/dsh-host-apiproxy/client'
+export type { SessionId, SessionEvent } from '@deepseek-ai/dsh-session/types'
+export type { ContentBlock, StreamChunk } from '@deepseek-ai/dsh-llm/types'
+
+import type { RpcResponse, RpcResult } from '@deepseek-ai/dsh-host-apiproxy/api'
+
+/**
+ * Unwrap a unary response: RpcResponse<T> -> RpcResult<T> (business code only
+ * cares about the result slot).
+ * @param response - the unary response.
+ * @returns its result slot.
+ */
+export function resultOf<T>(response: RpcResponse<T>): RpcResult<T> {
+  return response.result
+}
+
+/**
+ * Fold a transport exception into the RpcResult error branch (unified error
+ * surface; 'internal' as the catch-all code).
+ * @param error - the thrown value from the carrier.
+ * @returns the error branch of an RpcResult.
+ */
+export function transportError<T>(error: unknown): RpcResult<T> {
+  return {
+    ok: false,
+    error: { code: 'internal', message: error instanceof Error ? error.message : String(error), details: {} },
+  }
+}
+

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

@@ -0,0 +1,190 @@
+import type { IApiClient, HostFrame, MuxFrame, RpcRequest } from './api.ts'
+
+/** Reconnect/backoff tunables (deployment-varying — no hardcoded tunables; web-cordis §B.1 lists
+ *  these as the future `ctx.connection` plugin Config). All fields optional; defaults below. */
+export interface ConnectionConfig {
+  /** First-retry backoff cap in ms (jittered: actual delay is cap/2..cap). */
+  backoffBaseMs?: number
+  /** Exponential growth factor per consecutive failed attempt. */
+  backoffFactor?: number
+  /** Upper bound for the backoff cap in ms. */
+  backoffMaxMs?: number
+  /** Cap on waiting for both streams' onOpen before onConnected, in ms. The strict handshake
+   *  (audit C2) waits for mux+host stream establishment plus describe; a carrier that never
+   *  fires onOpen (misbehaving proxy) must not wedge the connection forever — on timeout the
+   *  generation proceeds as connected and the live-gap repair path (audit S3) covers stragglers. */
+  streamOpenTimeoutMs?: number
+}
+
+const CONNECTION_DEFAULTS: Required<ConnectionConfig> = {
+  backoffBaseMs: 500,
+  backoffFactor: 2,
+  backoffMaxMs: 10_000,
+  streamOpenTimeoutMs: 3_000,
+}
+
+function sleep(ms: number, signal: AbortSignal): Promise<void> {
+  return new Promise((resolve) => {
+    const t = setTimeout(done, ms)
+    signal.addEventListener('abort', done, { once: true })
+    function done(): void {
+      clearTimeout(t)
+      signal.removeEventListener('abort', done)
+      resolve()
+    }
+  })
+}
+
+/** Coarse connection state for the UI (audit C1): 'connected' after each generation's handshake,
+ *  'reconnecting' the moment the generation fails (covers the whole backoff+retry span). */
+export type ConnectionState = 'connected' | 'reconnecting'
+
+/** Frame sink callbacks: the Controller owns the physical streams; business dispatch belongs to
+ *  SessionManager. */
+export interface ConnectionSinks {
+  onMuxEnvelope?: (envelope: RpcRequest<MuxFrame>) => void
+  onHostEnvelope?: (envelope: RpcRequest<HostFrame>) => void
+  /** After each connection generation is established (both streams open + describe succeeded), first connect included. */
+  onConnected?: () => void
+  /** Coarse state transitions (deduplicated: fires only on change). The initial pre-connect
+   *  span reports nothing — the UI treats "no state yet" as connecting, not as an outage. */
+  onStateChange?: (state: ConnectionState) => void
+}
+
+/**
+ * Opens both streams and keeps iterating (pull mode: nothing reads the socket and the tap
+ * never fires unless someone for-awaits), reconnecting with exponential backoff on loss.
+ * State (generation/attempt) is instance-private, never in the store.
+ * The pump body feeds each frame to a sink (sink exceptions must
+ * not kill the pump — a broken business layer must not drag down the connection layer).
+ */
+export class ConnectionController {
+  private generation = 0
+  private attempt = 0
+  private current: AbortController | null = null
+  private running = false
+  private lastState: ConnectionState | null = null
+  private readonly config: Required<ConnectionConfig>
+
+  constructor(
+    private readonly api: IApiClient,
+    private readonly sinks: ConnectionSinks = {},
+    config: ConnectionConfig = {},
+  ) {
+    this.config = { ...CONNECTION_DEFAULTS, ...config }
+  }
+
+  /** Idempotent: begin the connect/pump/reconnect loop. */
+  start(): void {
+    if (this.running) return
+    this.running = true
+    void this.loop()
+  }
+
+  /** Stop the loop and abort the current generation's streams. */
+  stop(): void {
+    this.running = false
+    this.current?.abort()
+    this.current = null
+  }
+
+  private backoffDelay(attempt: number): number {
+    const { backoffBaseMs, backoffFactor, backoffMaxMs } = this.config
+    const cap = Math.min(backoffMaxMs, backoffBaseMs * backoffFactor ** Math.max(0, attempt - 1))
+    return cap / 2 + Math.random() * (cap / 2)
+  }
+
+  /** Read through a method: stop() flips the flag across awaits, so narrowing from the loop condition must not stick. */
+  private isRunning(): boolean {
+    return this.running
+  }
+
+  private async loop(): Promise<void> {
+    while (this.running) {
+      const gen = ++this.generation
+      const ac = new AbortController()
+      this.current = ac
+
+      /* v8 ignore next -- initializer placeholder: the Promise executor
+       * below runs synchronously and replaces it before anyone can call it. */
+      let muxOpened = (): void => {}
+      /* v8 ignore next -- same placeholder pattern as muxOpened. */
+      let hostOpened = (): void => {}
+      const streamsOpen = Promise.all([
+        new Promise<void>((resolve) => { muxOpened = resolve }),
+        new Promise<void>((resolve) => { hostOpened = resolve }),
+      ])
+
+      const failed = new Promise<void>((resolve) => {
+        const settle = (): void => {
+          if (gen === this.generation && !ac.signal.aborted) ac.abort()
+          resolve()
+        }
+        void this.pumpStream(this.api.events.mux({}, ac.signal, muxOpened), this.sinks.onMuxEnvelope, settle)
+        void this.pumpStream(this.api.events.host({}, ac.signal, hostOpened), this.sinks.onHostEnvelope, settle)
+      })
+
+      try {
+        // Strict readiness handshake (audit C2): describe proves unary reachability, onOpen
+        // proves each SSE transport is established (response headers in, before any frame) —
+        // only then may onConnected fire, so the resync it triggers cannot outrun the
+        // subscribed baseline. The timeout guards against a carrier that never fires onOpen
+        // (see ConnectionConfig.streamOpenTimeoutMs).
+        const timeout = new AbortController()
+        await Promise.all([
+          this.api.host.describe({}),
+          Promise.race([streamsOpen, sleep(this.config.streamOpenTimeoutMs, timeout.signal)]),
+        ])
+        timeout.abort()
+        if (ac.signal.aborted) throw new Error('generation aborted during readiness handshake')
+        this.attempt = 0
+        this.emitState('connected')
+        this.callSink(this.sinks.onConnected)
+      } catch {
+        // Transport failure: treat as generation failure, fall through to the shared backoff.
+        if (!ac.signal.aborted) ac.abort()
+      }
+
+      await failed
+      if (!this.isRunning()) return
+      this.emitState('reconnecting')
+      this.attempt += 1
+      console.warn(`[web-runtime] connection lost, retry #${this.attempt}`)
+      const idle = new AbortController()
+      await sleep(this.backoffDelay(this.attempt), idle.signal)
+    }
+  }
+
+  /** Deduplicated state emission (sink isolation applies). */
+  private emitState(state: ConnectionState): void {
+    if (this.lastState === state) return
+    this.lastState = state
+    this.callSink(() => this.sinks.onStateChange?.(state))
+  }
+
+  private async pumpStream<F extends { type: string }>(
+    stream: AsyncIterable<RpcRequest<F>>,
+    sink: ((envelope: RpcRequest<F>) => void) | undefined,
+    onEnd: () => void,
+  ): Promise<void> {
+    try {
+      for await (const envelope of stream) {
+        if (envelope.payload.type === 'stream/error') break
+        if (sink !== undefined) this.callSink(() => { sink(envelope) })
+      }
+    } catch {
+      // Stream loss: converge on onEnd, which triggers the shared reconnect.
+    }
+    onEnd()
+  }
+
+  /** Sink exception isolation: a business-layer throw is logged only, never affecting pump or reconnect semantics. */
+  private callSink(fn: (() => void) | undefined): void {
+    if (fn === undefined) return
+    try {
+      fn()
+    } catch (error) {
+      console.error('[web-runtime] connection sink threw:', error)
+    }
+  }
+}

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

@@ -0,0 +1,554 @@
+// FixtureApi: standalone UI development without a server. Real contract shape: unary takes
+// RpcRequest<P> and returns RpcResponse<T> (echoing the rpcId); streams yield RpcRequest<frame>
+// (the fixture IS the fake server, so it mints frame rpcIds); root respond takes ClientResponse
+// and returns RpcReceipt. fx-alpha carries a hand-built history script (60 turns, pageable);
+// prompt triggers a chunked streaming replay; cancel stops the replay; one resident pending
+// approval (placeholder-card material, subscribed-baseline-replay semantics: stable rpcId reuse).
+
+import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
+import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
+import type {
+  ApiProxy, ClientRequest, ClientResponse, HistoryEntry, HostFrame, MuxFrame, RpcReceipt,
+  RpcRequest, RpcResponse, RpcResult, ServerRequest, ServerResponse, SessionSummary,
+  ToolCallView, ToolEventView, ToolResultView,
+} from './api.ts'
+import type { RequestPayload, ResponseValue, RpcMethodMap } from '@deepseek-ai/dsh-host-apiproxy/api'
+import { AbstractApiClient, RpcId } from './api.ts'
+
+/** The fake carrier mints like a real one (business code never mints). */
+function rpcRequest<P>(payload: P): RpcRequest<P> {
+  return { rpcId: RpcId(crypto.randomUUID()), payload }
+}
+
+function text(t: string): ContentBlock[] {
+  return [{ type: 'text', text: t }]
+}
+
+function sid(id: string): SessionId {
+  return id as SessionId
+}
+
+/** fx-alpha history script: 60 turns (~130+ messages -> 3 pages at PAGE_MESSAGES=50),
+ *  mixing reasoning blocks / tool call+result / steering / context. */
+function buildAlphaLog(): SessionEvent[] {
+  const events: Record<string, unknown>[] = []
+  let time = Date.now() - 3_600_000
+  const push = (e: Record<string, unknown>): number => {
+    const seq = events.length
+    events.push({ seq, time: (time += 800), ...e })
+    return seq
+  }
+  for (let turn = 0; turn < 60; turn++) {
+    push({ type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
+    push({ type: 'user/message', surfaceOp: 'append', data: { content: text(`问题 ${turn}：fixture 历史消息，用于翻页与渲染验收。`), source: { kind: 'user' } } })
+    if (turn % 9 === 4) {
+      push({ type: 'context/message', surfaceOp: 'append', data: { content: text(`[fixture] 上下文注入（turn ${turn}）`), source: { kind: 'plugin', plugin: 'fixture' } } })
+    }
+    push({ type: 'step/start', data: { turn, step: 0 } })
+    const withTool = turn % 5 === 2
+    const withReasoning = turn % 3 === 1
+    const blocks: ContentBlock[] = []
+    if (withReasoning) blocks.push({ type: 'reasoning', text: `思考过程 ${turn}：这是一段可折叠的 reasoning 内容。` })
+    blocks.push({ type: 'text', text: `回答 ${turn}：这是 fixture 生成的历史回复正文。` })
+    if (withTool) {
+      const callId = `fx-call-${turn}`
+      blocks.push({ type: 'tool-call', id: callId, name: 'echo', arguments: `{"text":"turn ${turn}"}` } as ContentBlock)
+      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 0, content: blocks, provenance: { provider: 'fixture', model: 'fx-1' } } })
+      push({ type: 'tool/call', data: { turn, step: 0, callId, name: 'echo', arguments: `{"text":"turn ${turn}"}` } })
+      push({ type: 'tool/result', surfaceOp: 'append', data: { turn, step: 0, callId, content: text(`ECHO: TURN ${turn}`), isError: turn % 25 === 12 } })
+      push({ type: 'step/end', data: { turn, step: 0 } })
+      push({ type: 'step/start', data: { turn, step: 1 } })
+      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 1, content: text(`工具结果已消化（turn ${turn}）。`), provenance: { provider: 'fixture', model: 'fx-1' } } })
+      push({ type: 'step/end', data: { turn, step: 1 } })
+    } else {
+      push({ type: 'assistant/message', surfaceOp: 'append', data: { turn, step: 0, content: blocks, provenance: { provider: 'fixture', model: 'fx-1' } } })
+      push({ type: 'step/end', data: { turn, step: 0 } })
+    }
+    if (turn % 13 === 6) {
+      push({ type: 'steering/message', surfaceOp: 'append', data: { turn, content: text(`插话 ${turn}：fixture steering 消息。`), source: { kind: 'user' } } })
+    }
+    push({ type: 'turn/end', data: { turn, reason: { kind: 'completed' } } })
+  }
+  // Three view-sample turns (60-62) for the tool-card wire acceptance: one per built-in card
+  // type. `echo` above stays presenter-less on purpose — it is the no-view fallback sample.
+  const toolTurn = (turn: number, name: string, args: string, resultText: string): void => {
+    const callId = `fx-call-${turn}`
+    push({ type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
+    push({ type: 'user/message', surfaceOp: 'append', data: { content: text(`问题 ${turn}：${name} 样本。`), source: { kind: 'user' } } })
+    push({ type: 'step/start', data: { turn, step: 0 } })
+    push({
+      type: 'assistant/message', surfaceOp: 'append',
+      data: { turn, step: 0, content: [{ type: 'tool-call', id: callId, name, arguments: args } as ContentBlock], provenance: { provider: 'fixture', model: 'fx-1' } },
+    })
+    push({ type: 'tool/call', data: { turn, step: 0, callId, name, arguments: args } })
+    push({ type: 'tool/result', surfaceOp: 'append', data: { turn, step: 0, callId, content: text(resultText), isError: false } })
+    push({ type: 'step/end', data: { turn, step: 0 } })
+    push({ type: 'turn/end', data: { turn, reason: { kind: 'completed' } } })
+  }
+  toolTurn(60, 'fx-bash', '{"command":"ls -la","cwd":"/tmp/fixture"}', 'total 2\ndrwxr-xr-x fixture\n-rw-r--r-- demo.txt')
+  toolTurn(61, 'fx-write', '{"path":"notes/demo.txt","content":"hello fixture\\n"}', 'wrote notes/demo.txt')
+  toolTurn(62, 'fx-note', '{"note":"三型卡验收样本"}', '已记录')
+  return events as unknown as SessionEvent[]
+}
+
+/** Narrows a parsed-JSON field to string; fixture args are authored in-file, so non-strings only mean a typo here. */
+/* v8 ignore next -- the fallback arm is the same in-file-typo guard as the JSON.parse catch above. */
+const str = (value: unknown, fallback = ''): string => typeof value === 'string' ? value : fallback
+
+/** Fixture presenter registry (mirrors host viewFor): pure derivation, undefined = no view. */
+function presentCall(name: string, argsRaw: string): ToolCallView | undefined {
+  let args: Record<string, unknown>
+  try {
+    args = JSON.parse(argsRaw) as Record<string, unknown>
+  } catch {
+    /* v8 ignore next 2 -- defensive: fixture args are authored in-file as valid JSON; only an in-file typo could reach the catch. */
+    return undefined
+  }
+  switch (name) {
+    case 'fx-bash':
+      return { card: 'terminal', title: str(args.command), cwd: str(args.cwd, '/tmp/fixture'), description: 'fixture 终端样本' }
+    case 'fx-write':
+      return {
+        card: 'diff', title: `Write ${str(args.path)}`,
+        diffs: [{ path: str(args.path), oldText: null, newText: str(args.content) }],
+      }
+    case 'fx-note':
+      return { card: 'generic', title: '记录笔记', kind: 'edit', rawInput: args }
+    default:
+      return undefined // echo et al: the documented no-view fallback path
+  }
+}
+
+function presentResult(name: string, argsRaw: string, resultText: string): ToolResultView | undefined {
+  const call = presentCall(name, argsRaw)
+  if (call === undefined) return undefined
+  switch (call.card) {
+    case 'terminal':
+      return { card: 'terminal', output: resultText, exitCode: 0 }
+    case 'diff':
+      return { card: 'diff', diffs: call.diffs }
+    case 'generic':
+      return { card: 'generic', content: text(resultText) }
+  }
+}
+
+/** Host-side viewFor mirror: tool/call presents from its own args; tool/result back-scans the log for the paired call. */
+function viewFor(event: SessionEvent, log: readonly SessionEvent[]): ToolEventView | undefined {
+  if (event.type === 'tool/call') {
+    const view = presentCall(event.data.name, event.data.arguments)
+    return view === undefined ? undefined : { for: 'call', view }
+  }
+  if (event.type === 'tool/result') {
+    const callId = String(event.data.callId)
+    for (let i = log.length - 1; i >= 0; i--) {
+      const candidate = log[i]
+      /* v8 ignore next -- dense-array guard: i stays within [0, log.length),
+      so the undefined arm needs a sparse log no code path builds. */
+      if (candidate !== undefined && candidate.type === 'tool/call' && String(candidate.data.callId) === callId) {
+        const resultText = event.data.content.map(b => (b.type === 'text' ? b.text : '')).join('')
+        const view = presentResult(candidate.data.name, candidate.data.arguments, resultText)
+        return view === undefined ? undefined : { for: 'result', view }
+      }
+    }
+    return undefined // cross-page unpaired: documented default
+  }
+  return undefined
+}
+
+/**
+ * Message-boundary paging (mirrors the host's paging contract): count
+ * maxMessages messages
+ *  backwards from end, cut at a turn/start boundary.
+ Entries carry pagination-time views
+ *  (the host analogue computes viewFor per entry at page time). */
+function pageOf(
+  log: readonly SessionEvent[],
+  beforeSeq: number | undefined,
+  maxMessages: number,
+): { events: HistoryEntry[]; hasMore: boolean } {
+  const end = beforeSeq === undefined ? log.length : Math.max(0, Math.min(beforeSeq, log.length))
+  let start = 0
+  let messages = 0
+  for (let i = end - 1; i >= 0; i--) {
+    const event = log[i]
+    /* v8 ignore next -- dense-array guard: log seqs are array indexes, i stays within [0, end). */
+    if (event === undefined) break
+    if (event.type === 'user/message' || event.type === 'assistant/message' || event.type === 'steering/message') messages++
+    if (event.type === 'turn/start' && messages >= maxMessages) {
+      start = i
+      break
+    }
+  }
+  const events = log.slice(start, end).map((event): HistoryEntry => {
+    const view = viewFor(event, log)
+    return view === undefined ? { event } : { event, view }
+  })
+  return { events, hasMore: start > 0 }
+}
+
+interface StreamConn<F> {
+  push(envelope: RpcRequest<F>): void
+}
+
+/** Inbox pump shared by both stream generators (FrameQueue pattern: ONE abort listener hung
+ *  outside the loop — a per-iteration {once:true} listener never fires for non-final rounds and
+ *  piles up for the stream's lifetime, audit C5). breakNow force-ends the stream without the
+ *  client's signal (timing hook: simulated connection loss). */
+class FxInbox<F> implements StreamConn<F> {
+  private readonly inbox: RpcRequest<F>[] = []
+  private wake: (() => void) | null = null
+  private broken = false
+
+  push(envelope: RpcRequest<F>): void {
+    this.inbox.push(envelope)
+    this.wake?.()
+  }
+
+  breakNow(): void {
+    this.broken = true
+    this.wake?.()
+  }
+
+  /** Read through a method: breakNow()/abort flip state across yields, so narrowing from the loop condition must not stick. */
+  private isLive(signal: AbortSignal): boolean {
+    return !signal.aborted && !this.broken
+  }
+
+  async *drain(signal: AbortSignal): AsyncGenerator<RpcRequest<F>> {
+    const onAbort = (): void => this.wake?.()
+    signal.addEventListener('abort', onAbort)
+    try {
+      while (this.isLive(signal)) {
+        while (this.inbox.length > 0) yield this.inbox.shift() as RpcRequest<F>
+        if (!this.isLive(signal)) break
+        await new Promise<void>((resolve) => {
+          this.wake = resolve
+        })
+        this.wake = null
+      }
+    } finally {
+      signal.removeEventListener('abort', onAbort)
+    }
+  }
+}
+
+/**
+ * In-memory fake host: fx-alpha carries history and replay scripts; fx-beta is fx-alpha's child session (lineage indent material).
+ * @returns an ApiProxy backed entirely by in-memory state — no host process, no network.
+ */
+export function createFixtureApi(): ApiProxy {
+  const sessions: SessionSummary[] = [
+    { sessionId: sid('fx-alpha'), updatedAt: Date.now(), running: true, cwd: '/tmp/fixture' },
+    { sessionId: sid('fx-beta'), updatedAt: Date.now() - 60_000, running: false, parentSessionId: sid('fx-alpha'), cwd: '/tmp/fixture' },
+    { sessionId: sid('fx-gamma'), updatedAt: Date.now() - 120_000, running: false, cwd: '/tmp/fixture' },
+  ]
+  const logs = new Map<SessionId, SessionEvent[]>([[sid('fx-alpha'), buildAlphaLog()]])
+  const nextTurn = new Map<SessionId, number>([[sid('fx-alpha'), 60]])
+  let nextSession = 1
+  let nextRpc = 1
+  const mint = (): ReturnType<typeof RpcId> => RpcId(`fx-rpc-${nextRpc++}`)
+  /** Resident pending approval (stable rpcId: every mux open replays the same id, matching host replay semantics). */
+  const pendingApprovalRpcId = mint()
+
+  const muxConns = new Set<StreamConn<MuxFrame>>()
+  const hostConns = new Set<StreamConn<HostFrame>>()
+  const emitMux = (frame: MuxFrame): void => {
+    for (const conn of muxConns) conn.push({ rpcId: mint(), payload: frame })
+  }
+  const emitHost = (frame: HostFrame): void => {
+    for (const conn of hostConns) conn.push({ rpcId: mint(), payload: frame })
+  }
+
+  /** OK response echoing the caller's rpcId (contract: responses always backfill, never mint). */
+  function ok<P, T>(request: RpcRequest<P>, value: T): Promise<RpcResponse<T>> {
+    return Promise.resolve({ rpcId: request.rpcId, result: { ok: true, value } })
+  }
+  function err<P, T>(request: RpcRequest<P>, error: Extract<RpcResult<T>, { ok: false }>['error']): Promise<RpcResponse<T>> {
+    return Promise.resolve({ rpcId: request.rpcId, result: { ok: false, error } })
+  }
+
+  const summaryOf = (id: SessionId): SessionSummary | undefined => sessions.find(s => s.sessionId === id)
+  const setRunning = (id: SessionId, running: boolean): void => {
+    const summary = summaryOf(id)
+    if (summary === undefined || summary.running === running) return
+    summary.running = running
+    emitHost({ type: 'host/session-status', sessionId: id, running })
+  }
+  const logOf = (id: SessionId): SessionEvent[] => {
+    let log = logs.get(id)
+    if (log === undefined) {
+      log = []
+      logs.set(id, log)
+    }
+    return log
+  }
+  const append = (id: SessionId, e: Record<string, unknown>): void => {
+    const log = logOf(id)
+    const event = { seq: log.length, time: Date.now(), ...e } as unknown as SessionEvent
+    log.push(event)
+    // Emission-time view derivation (mirrors the host's live path).
+    const view = viewFor(event, log)
+    /* v8 ignore next 3 -- the view-present arm needs a live tool/call emission,
+    but the fixture replay produces text-only turns; view vocabulary is
+    exercised through the history samples (turns 60-62). */
+    emitMux(view === undefined
+      ? { type: 'session/event', sessionId: id, event }
+      : { type: 'session/event', sessionId: id, event, view })
+  }
+
+  /** At most one in-flight replay per session; cancel clears it. */
+  const replays = new Map<SessionId, { timer: ReturnType<typeof setTimeout>; finish(aborted: boolean): void }>()
+
+  /** history transit delay (timing hooks below); the page snapshot is taken at request time, like a real host. */
+  let historyDelayMs = 0
+  /** One-shot history failure (timing hook: the doomed in-flight request of the S4 reconnect scenario). */
+  let failNextHistory = false
+  /** Force-enders for currently open stream generators (timing hook: simulated connection loss). */
+  const streamBreakers = new Set<() => void>()
+
+  // Timing-acceptance hooks (browser test backdoor): the in-memory fixture is ideally timed, which
+  // is exactly what masked the open-window and reconnect-gap bugs (audit S1/S3). These let
+  // browser acceptance runs create slow-history, lost-frame, and reconnect
+  // windows a real host produces naturally.
+  const timingHooks = {
+    setHistoryDelay(ms: number): void {
+      historyDelayMs = ms
+    },
+    /** Fail the NEXT history call (after its transit delay) with a transport-level throw. */
+    failNextHistory(): void {
+      failNextHistory = true
+    },
+    /** Log append + mux emit (the normal live path). */
+    appendUser(id: string, msg: string): void {
+      append(sid(id), { type: 'user/message', surfaceOp: 'append', data: { content: text(msg), source: { kind: 'user' } } })
+    },
+    /** Log append WITHOUT the mux emit: a frame lost in transit — history still serves it, the client must repull. */
+    appendSilent(id: string, msg: string): void {
+      const log = logOf(sid(id))
+      log.push({ type: 'user/message', surfaceOp: 'append', seq: log.length, time: Date.now(), data: { content: text(msg), source: { kind: 'user' } } } as unknown as SessionEvent)
+    },
+    /** End every open stream generator (client sees both streams close -> reconnect + resync path). */
+    breakStreams(): void {
+      for (const breakNow of [...streamBreakers]) breakNow()
+    },
+  }
+  ;(globalThis as Record<string, unknown>).__fxTiming = timingHooks
+
+  /** Prompt replay: chunk typewriter (80ms/frame) -> assistant/message finalize -> turn/end + running flip. */
+  const startReply = (id: SessionId, turn: number, replyText: string): void => {
+    const step = 0
+    append(id, { type: 'step/start', data: { turn, step } })
+    append(id, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'block-start', index: 0, blockType: 'text' } } })
+    /* v8 ignore next -- the ?? arm needs a null match, but replyText is never empty (prompt always prefixes 回声). */
+    const pieces = replyText.match(/.{1,6}/gu) ?? [replyText]
+    let i = 0
+    const finish = (aborted: boolean): void => {
+      replays.delete(id)
+      const done = pieces.slice(0, i).join('')
+      append(id, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'block-end', index: 0, block: { type: 'text', text: done } } } })
+      append(id, { type: 'assistant/message', surfaceOp: 'append', data: { turn, step, content: text(aborted ? `${done}（已中断）` : done), provenance: { provider: 'fixture', model: 'fx-1' } } })
+      append(id, { type: 'step/end', data: { turn, step } })
+      append(id, { type: 'turn/end', data: { turn, reason: { kind: aborted ? 'cancelled' : 'completed' } } })
+      setRunning(id, false)
+    }
+    const tick = (): void => {
+      const piece = pieces[i]
+      if (piece === undefined) {
+        finish(false)
+        return
+      }
+      i++
+      append(id, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'text-delta', index: 0, text: piece } } })
+      replays.set(id, { timer: setTimeout(tick, 80), finish })
+    }
+    replays.set(id, { timer: setTimeout(tick, 80), finish })
+  }
+
+  return {
+    sessions: {
+      list: request => ok(request, { items: [...sessions].sort((a, b) => b.updatedAt - a.updatedAt) }),
+      create: (request) => {
+        const created: SessionSummary = {
+          sessionId: sid(`fx-${nextSession++}`), updatedAt: Date.now(), running: false, cwd: '/tmp/fixture',
+        }
+        sessions.push(created)
+        emitHost({ type: 'host/session-added', sessionId: created.sessionId })
+        return ok(request, { sessionId: created.sessionId })
+      },
+      history: async (request) => {
+        const log = logs.get(request.payload.sessionId) ?? []
+        // Snapshot at request time, deliver after the transit delay (mirrors a real host under latency).
+        const page = pageOf(log, request.payload.beforeSeq, request.payload.maxMessages ?? 50)
+        const doomed = failNextHistory
+        failNextHistory = false
+        const delay = historyDelayMs
+        if (delay > 0) await new Promise(resolve => setTimeout(resolve, delay))
+        if (doomed) throw new Error('fixture: simulated history transport failure')
+        return ok(request, page)
+      },
+      prompt: (request) => {
+        const { sessionId: id, mode, content } = request.payload
+        const summary = summaryOf(id)
+        if (summary === undefined) {
+          return err(request, { code: 'session-not-found', message: `no session ${id}`, details: { sessionId: id } })
+        }
+        summary.updatedAt = Date.now()
+        const userText = content.map(b => (b.type === 'text' ? b.text : '')).join('')
+        if (mode === 'steer' && replays.has(id)) {
+          // Steering: insert a steering message into the current turn; the replay continues.
+          /* v8 ignore next -- the ?? arm needs a missing counter, but a live replay implies a prior prompt already set it. */
+          const turn = (nextTurn.get(id) ?? 1) - 1
+          append(id, { type: 'steering/message', surfaceOp: 'append', data: { turn, content, source: { kind: 'user' } } })
+          return ok(request, { accepted: true as const })
+        }
+        const turn = nextTurn.get(id) ?? 0
+        nextTurn.set(id, turn + 1)
+        setRunning(id, true)
+        append(id, { type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } })
+        append(id, { type: 'user/message', surfaceOp: 'append', data: { content, source: { kind: 'user' } } })
+        startReply(id, turn, `回声：${userText}。这是 fixture 的流式回复，用于验证打字机增长与定稿切换。`)
+        return ok(request, { accepted: true as const })
+      },
+      cancel: (request) => {
+        const replay = replays.get(request.payload.sessionId)
+        if (replay !== undefined) {
+          clearTimeout(replay.timer)
+          replay.finish(true)
+        } else {
+          setRunning(request.payload.sessionId, false)
+        }
+        return ok(request, { accepted: true as const })
+      },
+    },
+    host: {
+      describe: request => ok(request, { version: '0.0.0-fixture', cwd: '/tmp/fixture', attachedSessions: 1 }),
+    },
+    events: {
+      async *mux(_request, signal) {
+        const conn = new FxInbox<MuxFrame>()
+        muxConns.add(conn)
+        const breakNow = (): void => { conn.breakNow() }
+        streamBreakers.add(breakNow)
+        // Open baseline: subscribed for attached (running) sessions + pending approval replay (stable rpcId).
+        for (const s of sessions) {
+          if (!s.running) continue
+          conn.push({ rpcId: mint(), payload: { type: 'session/subscribed', sessionId: s.sessionId, lastSeq: (logs.get(s.sessionId)?.length ?? 0) - 1 } })
+        }
+        conn.push({
+          rpcId: pendingApprovalRpcId,
+          payload: {
+            type: 'approval/requested', sessionId: sid('fx-alpha'),
+            approvalId: 'fx-approval-1' as MuxFrame extends never ? never : Extract<MuxFrame, { type: 'approval/requested' }>['approvalId'],
+            toolName: 'dangerous_tool', reason: 'fixture 常驻占位审批（可见不可答）',
+          },
+        })
+        try {
+          yield* conn.drain(signal)
+        } finally {
+          streamBreakers.delete(breakNow)
+          muxConns.delete(conn)
+        }
+      },
+      async *host(_request, signal) {
+        const conn = new FxInbox<HostFrame>()
+        hostConns.add(conn)
+        const breakNow = (): void => { conn.breakNow() }
+        streamBreakers.add(breakNow)
+        // Periodic material (the RPC-panel acceptance's clear-then-new-frames step depends on it): flip fx-gamma every 5s.
+        // fx-gamma only: never touch fx-alpha's running semantics (the conversation replay drives that).
+        const timer = setInterval(() => {
+          const gamma = summaryOf(sid('fx-gamma'))
+          /* v8 ignore next -- the undefined arm needs fx-gamma deleted, but the fixture never removes sessions. */
+          if (gamma !== undefined) setRunning(gamma.sessionId, !gamma.running)
+        }, 5000)
+        try {
+          yield* conn.drain(signal)
+        } finally {
+          clearInterval(timer)
+          streamBreakers.delete(breakNow)
+          hostConns.delete(conn)
+        }
+      },
+    },
+    respond(message: ClientResponse): Promise<RpcReceipt> {
+      // The v1 UI never answers (PendingCard is visible but not answerable); implemented for type completeness, always not-pending.
+      void message
+      return Promise.resolve({ accepted: false, reason: 'not-pending' })
+    },
+  }
+}
+
+/**
+ * Fixture platform subclass: there is no HTTP at all, so instead of a doFetch transport it
+ * overrides the protocol-level virtuals (callUnary/openMux/openHost/respond) to dispatch
+ * straight into the in-memory ApiProxy — while still minting rpcIds, fabricating the four
+ * named full forms, and feeding the same tap as a real carrier. Delete when the fixture moves
+ * to the isomorphic pipeline (InProcessApiClient over toFetchHandler(fixtureImpl)).
+ */
+export class FixtureApiClient extends AbstractApiClient {
+  private readonly api = createFixtureApi()
+
+  protected doFetch(): Promise<Response> {
+    throw new Error('FixtureApiClient overrides all protocol paths; doFetch must be unreachable')
+  }
+
+  protected override async callUnary<K extends keyof RpcMethodMap>(
+    method: K,
+    payload: RequestPayload<K>,
+  ): Promise<RpcResponse<ResponseValue<K>>> {
+    const request = rpcRequest(payload)
+    const full: ClientRequest = { type: 'client-request', rpcId: request.rpcId, method, payload }
+    this.onEnvelope(full)
+    const response = await this.dispatch(method, request as RpcRequest<never>) as RpcResponse<ResponseValue<K>>
+    const fullResponse: ServerResponse = { type: 'server-response', rpcId: response.rpcId, result: response.result }
+    this.onEnvelope(fullResponse)
+    return response
+  }
+
+  /** Method-key dispatch into the in-memory contract impl (a real carrier routes by URL path instead). */
+  private dispatch(method: keyof RpcMethodMap, request: RpcRequest<never>): Promise<RpcResponse<unknown>> {
+    switch (method) {
+      case 'session.list': return this.api.sessions.list(request)
+      case 'session.create': return this.api.sessions.create(request)
+      case 'session.history': return this.api.sessions.history(request)
+      case 'session.prompt': return this.api.sessions.prompt(request)
+      case 'session.cancel': return this.api.sessions.cancel(request)
+      case 'host.describe': return this.api.host.describe(request)
+    }
+  }
+
+  protected override openMux(
+    payload: { since?: Record<SessionId, number> },
+    signal: AbortSignal,
+    onOpen?: () => void,
+  ): AsyncIterable<RpcRequest<MuxFrame>> {
+    return this.tapStream(this.api.events.mux(rpcRequest(payload), signal), onOpen)
+  }
+
+  protected override openHost(
+    payload: Record<never, never>,
+    signal: AbortSignal,
+    onOpen?: () => void,
+  ): AsyncIterable<RpcRequest<HostFrame>> {
+    return this.tapStream(this.api.events.host(rpcRequest(payload), signal), onOpen)
+  }
+
+  private async *tapStream<F extends MuxFrame | HostFrame>(
+    stream: AsyncIterable<RpcRequest<F>>,
+    onOpen?: () => void,
+  ): AsyncGenerator<RpcRequest<F>> {
+    // No HTTP here: the in-memory stream is established the moment iteration starts (mirrors
+    // readSse firing onOpen after response headers, before any frame).
+    onOpen?.()
+    for await (const envelope of stream) {
+      const full: ServerRequest = { type: 'server-request', rpcId: envelope.rpcId, method: envelope.payload.type, payload: envelope.payload }
+      this.onEnvelope(full)
+      yield envelope
+    }
+  }
+
+  override async respond(message: ClientResponse): Promise<RpcReceipt> {
+    this.onEnvelope(message)
+    return this.api.respond(message)
+  }
+}

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

@@ -0,0 +1,76 @@
+/**
+ * Browser half of the wire consumer layer (contract: api-contracts v3
+ * section 3; export inventory = v3 §3.2). The wire is this package's client
+ * half in its entirety — apply mounts ctx.connection: the shared api client
+ * plus the connection controller handle. Mode selection (?fixture) happens
+ * here so the rest of the client tree is mode-blind; the controller's sinks
+ * are wired by the runtime plugin (object layer), which injects this service.
+ */
+import type { Context } from 'cordis'
+import type { IApiClient } from './api.ts'
+import { ConnectionController, type ConnectionConfig, type ConnectionSinks, type ConnectionState } from './connection.ts'
+import { FixtureApiClient } from './fixture.ts'
+import { WebApiClient } from './web-api-client.ts'
+
+// ---- Contract re-exports (browser-safe apiproxy channels + core types) ----
+export type {
+  ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
+  ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
+  ToolCallView, ToolResultView,
+  RpcRequest, RpcResponse, RpcResult, RpcError, RpcErrorCode,
+  ClientRequest, ServerResponse, ServerRequest, ClientResponse, RpcMessage, RpcReceipt,
+  IApiClient, SessionId, SessionEvent, ContentBlock, StreamChunk,
+} from './api.ts'
+export { RpcId, AbstractApiClient, resultOf, transportError } from './api.ts'
+
+// ---- Connection loop ----
+export { ConnectionController } from './connection.ts'
+export type { ConnectionConfig, ConnectionSinks, ConnectionState }
+
+// ---- Platform client subclasses ----
+export { WebApiClient } from './web-api-client.ts'
+export { FixtureApiClient, createFixtureApi } from './fixture.ts'
+
+
+/** Required services (none — this is the wire root). */
+export const inject: string[] = []
+
+/**
+ * The ctx.connection service surface: the api client plus a one-shot
+ * controller starter (the runtime plugin supplies sinks when its object layer
+ * is ready — connection stays consumer-agnostic).
+ */
+export interface ConnectionHandle {
+  /** Shared api client (fixture or real, decided at boot from the page URL). */
+  readonly api: IApiClient
+  /**
+   * Start the connect/pump/reconnect loop with the consumer's frame sinks.
+   * One consumer owns the streams (the runtime object layer); a second call
+   * throws.
+   * @param sinks - frame/state callbacks.
+   * @param config - reconnect/backoff tunables.
+   * @returns stop handle for the loop.
+   */
+  start(sinks: ConnectionSinks, config?: ConnectionConfig): { stop(): void }
+}
+
+/**
+ * Client plugin body: pick the api by page mode and provide ctx.connection.
+ * @param ctx - client cordis context.
+ */
+export function apply(ctx: Context): void {
+  const fixture = typeof location !== 'undefined' && new URLSearchParams(location.search).has('fixture')
+  const api: IApiClient = fixture ? new FixtureApiClient() : new WebApiClient()
+  let started = false
+  const handle: ConnectionHandle = {
+    api,
+    start(sinks, config) {
+      if (started) throw new Error('connection: the stream loop is already owned by another consumer')
+      started = true
+      const controller = new ConnectionController(api, sinks, config ?? {})
+      controller.start()
+      return { stop: () => { controller.stop() } }
+    },
+  }
+  ctx.provide('connection', handle)
+}

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

@@ -0,0 +1,12 @@
+// WebApiClient: the browser platform subclass — transport = global fetch over same-origin
+// /api/* (base resolution handled by AbstractApiClient). Envelope observation comes from the
+// base batching aspect; subscribers attach via subscribeEnvelopes (see boot).
+
+import { AbstractApiClient } from './api.ts'
+
+/** Browser platform subclass: transport = global fetch over same-origin /api/*. */
+export class WebApiClient extends AbstractApiClient {
+  protected doFetch(input: URL, init?: RequestInit): Promise<Response> {
+    return globalThis.fetch(input, init)
+  }
+}

packages/client/connection/src/index.ts

@@ -0,0 +1,10 @@
+/**
+ * Connection plugin, node half. The package IS a dshClient plugin: the wire
+ * consumer layer lives in its client half in full (src/client/ — contract:
+ * api-contracts v3 section 3, inventory §3.2); consumers import the /client
+ * subpath. The empty apply exists so the plugin appears in the host Loader
+ * (lifecycle governance + dshClient discovery).
+ */
+
+/** Host plugin body — no host-side behavior for the connection plugin. */
+export function apply(_ctx: unknown): void {}

packages/client/connection/src/invariant.ts

@@ -0,0 +1,32 @@
+/**
+ * Package-owned invariant companion for `@deepseek-ai/dsh-client-connection`.
+ * @module @deepseek-ai/dsh-client-connection/invariant
+ */
+
+/* jscpd:ignore-start */
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-client-connection'
+
+/** Cordis companion plugin name. */
+export const name = 'client-connection-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/**
+ * No runtime invariant: the pure wire layer emits no cordis events and owns no
+ * mutable cross-plugin relation — stream/reconnect sequencing is exercised
+ * directly by its behavior specs, and rpcId round-trip discipline is owned by
+ * the apiproxy contract layer.
+ */
+const install: InvariantInstaller = () => {}
+
+/**
+ * Register this package's invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))
+/* jscpd:ignore-end */

packages/client/connection/tests/api-helpers.spec.ts

@@ -0,0 +1,21 @@
+/**
+ * Contract-layer helpers: transport-error folding and response unwrapping.
+ * (The assistant block classifier half of the legacy spec lives in
+ * runtime/tests — the classifier moved there.)
+ */
+
+import { describe, expect, it } from 'vitest'
+import { RpcId, resultOf, transportError } from '../src/client/api.ts'
+
+describe('transportError', () => {
+  it('folds an Error to internal keeping the message, and stringifies non-Errors', () => {
+    expect(transportError(new Error('线断了'))).toEqual({ ok: false, error: { code: 'internal', message: '线断了', details: {} } })
+    expect(transportError('raw string')).toMatchObject({ ok: false, error: { message: 'raw string' } })
+  })
+})
+
+describe('resultOf', () => {
+  it('unwraps the result slot', () => {
+    expect(resultOf({ rpcId: RpcId('r'), result: { ok: true, value: 7 } })).toEqual({ ok: true, value: 7 })
+  })
+})

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

@@ -0,0 +1,238 @@
+/**
+ * ConnectionController: stream pumping into sinks, the strict readiness
+ * handshake (describe + both streams' onOpen, timeout-guarded), generation
+ * abort on loss, backoff reconnection, state transitions, and sink-exception
+ * isolation. Real (short) timers — the timeout and backoff are configurable,
+ * so tests run them at millisecond scale.
+ */
+
+import { describe, expect, it, vi } from 'vitest'
+import type { SessionId } from '../src/client/api.ts'
+import type { ConnectionState } from '../src/client/connection.ts'
+import { ConnectionController } from '../src/client/connection.ts'
+import { FakeApiClient, deferred, ok } from './fake-api.ts'
+
+const SID = 'fk-c1' as SessionId
+const FAST = { backoffBaseMs: 10, backoffFactor: 1, backoffMaxMs: 10, streamOpenTimeoutMs: 500 }
+
+function subscribedFrame(lastSeq = 0) {
+  return { type: 'session/subscribed', sessionId: SID, lastSeq } as const
+}
+
+describe('connection lifecycle', () => {
+  it('announces connected after describe + both streams open, then pumps frames to sinks', async () => {
+    const api = new FakeApiClient()
+    const muxSeen: string[] = []
+    let connected = 0
+    const controller = new ConnectionController(api, {
+      onMuxEnvelope: envelope => muxSeen.push(envelope.payload.type),
+      onConnected: () => { connected++ },
+    }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+      api.pushMux(subscribedFrame())
+      await vi.waitFor(() => { expect(muxSeen).toEqual(['session/subscribed']) })
+      expect(api.callsOf('host.describe')).toHaveLength(1)
+    } finally {
+      controller.stop()
+    }
+  })
+
+  it('reconnects with a fresh generation when a stream fails, and stop() ends the loop', async () => {
+    const api = new FakeApiClient()
+    let connected = 0
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const controller = new ConnectionController(api, { onConnected: () => { connected++ } }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+      api.failStreams(new Error('stream torn'))
+      await vi.waitFor(() => { expect(connected).toBe(2) }) // new generation after backoff
+      expect(api.openMuxCount).toBe(1) // the dead generation's stream is gone, exactly one live
+    } finally {
+      controller.stop()
+      warnSpy.mockRestore()
+    }
+    // stop() aborts the live generation (streams tear down) and no reconnect follows.
+    await vi.waitFor(() => { expect(api.openMuxCount).toBe(0) })
+    await new Promise(resolve => setTimeout(resolve, 40))
+    expect(api.openMuxCount).toBe(0)
+  })
+
+  it('treats describe failure as generation failure and retries', async () => {
+    const api = new FakeApiClient()
+    const gate = deferred<Awaited<ReturnType<FakeApiClient['onDescribe']>>>()
+    let describeCalls = 0
+    api.onDescribe = () => {
+      describeCalls++
+      return describeCalls === 1 ? Promise.reject(new Error('host down')) : gate.promise
+    }
+    let connected = 0
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const controller = new ConnectionController(api, { onConnected: () => { connected++ } }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(describeCalls).toBe(2) }) // retried after backoff
+      expect(connected).toBe(0) // never announced during the failed generation
+      gate.resolve(ok({ version: '0', cwd: '/f', attachedSessions: 0 }))
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+    } finally {
+      controller.stop()
+      warnSpy.mockRestore()
+    }
+  })
+
+  it('converges stream/error frames into reconnect instead of dispatching them', async () => {
+    const api = new FakeApiClient()
+    const muxSeen: string[] = []
+    let connected = 0
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const controller = new ConnectionController(api, {
+      onMuxEnvelope: envelope => muxSeen.push(envelope.payload.type),
+      onConnected: () => { connected++ },
+    }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+      api.pushMux({ type: 'stream/error', error: { code: 'internal', message: 'impl broke', details: {} } })
+      await vi.waitFor(() => { expect(connected).toBe(2) }) // treated as loss → reconnect
+      expect(muxSeen).toEqual([]) // never forwarded to the business sink
+    } finally {
+      controller.stop()
+      warnSpy.mockRestore()
+    }
+  })
+
+  it('isolates sink exceptions from the pump', async () => {
+    const api = new FakeApiClient()
+    const seen: string[] = []
+    let connected = 0
+    const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
+    const controller = new ConnectionController(api, {
+      onMuxEnvelope: (envelope) => {
+        seen.push(envelope.payload.type)
+        throw new Error('business layer bug')
+      },
+      onConnected: () => { connected++ },
+    }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+      api.pushMux(subscribedFrame(1))
+      api.pushMux(subscribedFrame(2))
+      await vi.waitFor(() => { expect(seen).toHaveLength(2) }) // second frame still pumped
+      expect(connected).toBe(1) // no reconnect triggered by the sink throw
+    } finally {
+      controller.stop()
+      errorSpy.mockRestore()
+    }
+  })
+
+  it('holds onConnected until both streams establish even after describe succeeds', async () => {
+    const api = new FakeApiClient()
+    api.holdStreamOpen = true // describe resolves immediately; stream establishment is in the case's hand
+    let connected = 0
+    const controller = new ConnectionController(api, { onConnected: () => { connected++ } }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(api.callsOf('host.describe')).toHaveLength(1) })
+      await new Promise(resolve => setTimeout(resolve, 30))
+      expect(connected).toBe(0) // describe alone must not announce
+      api.releaseStreamOpens()
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+    } finally {
+      controller.stop()
+    }
+  })
+
+  it('proceeds as connected via the timeout guard when a carrier never fires onOpen', async () => {
+    const api = new FakeApiClient()
+    api.suppressStreamOpen = true // misbehaving carrier: streams open but onOpen never fires
+    let connected = 0
+    const controller = new ConnectionController(api, { onConnected: () => { connected++ } }, { ...FAST, streamOpenTimeoutMs: 20 })
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(connected).toBe(1) }) // handshake resolved by the guard, not wedged
+    } finally {
+      controller.stop()
+    }
+  })
+
+  it('emits deduplicated connected/reconnecting state transitions', async () => {
+    const api = new FakeApiClient()
+    const states: ConnectionState[] = []
+    let connected = 0
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const controller = new ConnectionController(api, {
+      onConnected: () => { connected++ },
+      onStateChange: state => states.push(state),
+    }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+      expect(states).toEqual(['connected'])
+      api.failStreams(new Error('torn'))
+      await vi.waitFor(() => { expect(connected).toBe(2) })
+      expect(states).toEqual(['connected', 'reconnecting', 'connected'])
+    } finally {
+      controller.stop()
+      warnSpy.mockRestore()
+    }
+  })
+
+  it('deduplicates consecutive reconnecting emissions across two straight failures', async () => {
+    const api = new FakeApiClient()
+    const gate = deferred<Awaited<ReturnType<FakeApiClient['onDescribe']>>>()
+    let describeCalls = 0
+    api.onDescribe = () => {
+      describeCalls++
+      return describeCalls <= 2 ? Promise.reject(new Error('down')) : gate.promise
+    }
+    const states: ConnectionState[] = []
+    let connected = 0
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const controller = new ConnectionController(api, {
+      onConnected: () => { connected++ },
+      onStateChange: state => states.push(state),
+    }, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(describeCalls).toBe(3) })
+      gate.resolve(ok({ version: '0', cwd: '/f', attachedSessions: 0 }))
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+      expect(states).toEqual(['reconnecting', 'connected']) // two failures, one reconnecting emission
+    } finally {
+      controller.stop()
+      warnSpy.mockRestore()
+    }
+  })
+
+  it('runs with no sinks at all (every callback slot optional)', async () => {
+    const api = new FakeApiClient()
+    const controller = new ConnectionController(api, {}, FAST)
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(api.callsOf('host.describe')).toHaveLength(1) })
+      api.pushMux(subscribedFrame()) // pumped with sink undefined: dropped silently
+      await new Promise(resolve => setTimeout(resolve, 20))
+    } finally {
+      controller.stop()
+    }
+  })
+
+  it('start() is idempotent (one loop, one stream set)', async () => {
+    const api = new FakeApiClient()
+    let connected = 0
+    const controller = new ConnectionController(api, { onConnected: () => { connected++ } }, FAST)
+    controller.start()
+    controller.start()
+    try {
+      await vi.waitFor(() => { expect(connected).toBe(1) })
+      expect(api.openMuxCount).toBe(1)
+      expect(api.callsOf('host.describe')).toHaveLength(1)
+    } finally {
+      controller.stop()
+    }
+  })
+})

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

@@ -0,0 +1,154 @@
+// 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 {
+  HostFrame, IApiClient, MuxFrame, RpcRequest, RpcResponse, SessionId,
+} from '../src/client/api.ts'
+import { RpcId } from '../src/client/api.ts'
+
+export interface Deferred<T> {
+  promise: Promise<T>
+  resolve(value: T): void
+  reject(error: unknown): void
+}
+
+/** Test-held settlement: the case decides when an RPC lands (history-pending injections etc.). */
+export function deferred<T>(): Deferred<T> {
+  let resolve!: (value: T) => void
+  let reject!: (error: unknown) => void
+  const promise = new Promise<T>((res, rej) => {
+    resolve = res
+    reject = rej
+  })
+  return { promise, resolve, reject }
+}
+
+let nextRpc = 0
+
+export function ok<T>(value: T): RpcResponse<T> {
+  return { rpcId: RpcId(`fake-${nextRpc++}`), result: { ok: true, value } }
+}
+
+
+type StreamItem<F> = { kind: 'frame'; envelope: RpcRequest<F> } | { kind: 'end' } | { kind: 'fail'; error: unknown }
+
+interface StreamConn<F> {
+  feed(item: StreamItem<F>): void
+}
+
+export class FakeApiClient implements IApiClient {
+  /** Chronological call record: [method, payload]. */
+  readonly calls: { method: string; payload: unknown }[] = []
+
+  // 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 }))
+  onHistory: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number })
+  => Promise<RpcResponse<{ events: never[]; hasMore: boolean }>> =
+    () => Promise.resolve(ok({ events: [], hasMore: false }))
+
+  onPrompt: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
+  onCancel: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
+  onDescribe: (payload: unknown) => Promise<RpcResponse<{ version: string; cwd: string; attachedSessions: number }>> =
+    () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0 }))
+
+  private readonly muxConns: StreamConn<MuxFrame>[] = []
+  private readonly hostConns: StreamConn<HostFrame>[] = []
+
+  readonly sessions: IApiClient['sessions'] = {
+    list: payload => this.record('session.list', payload, this.onList(payload)),
+    create: payload => this.record('session.create', payload, this.onCreate(payload)),
+    history: payload => this.record('session.history', payload, this.onHistory(payload)),
+    prompt: payload => this.record('session.prompt', payload, this.onPrompt(payload)),
+    cancel: payload => this.record('session.cancel', payload, this.onCancel(payload)),
+  }
+
+  readonly host: IApiClient['host'] = {
+    describe: payload => this.record('host.describe', payload, this.onDescribe(payload)),
+  }
+
+  /** When true, streams never fire onOpen (misbehaving-carrier material for the handshake timeout guard). */
+  suppressStreamOpen = false
+
+  /** When true, onOpen callbacks are parked instead of fired; releaseStreamOpens() fires them.
+   *  Lets a case hold the readiness handshake open (describe done, streams not yet "established"). */
+  holdStreamOpen = false
+  private heldOpens: (() => void)[] = []
+
+  releaseStreamOpens(): void {
+    const held = this.heldOpens
+    this.heldOpens = []
+    for (const fire of held) fire()
+  }
+
+  readonly events: IApiClient['events'] = {
+    mux: (_payload, signal, onOpen) => this.openStream(this.muxConns, signal, onOpen),
+    host: (_payload, signal, onOpen) => this.openStream(this.hostConns, signal, onOpen),
+  }
+
+  respond(): Promise<{ accepted: false; reason: 'not-pending' }> {
+    return Promise.resolve({ accepted: false, reason: 'not-pending' })
+  }
+
+  /** Push one mux frame to every open mux stream (rpcId minted unless pinned by the case). */
+  pushMux(frame: MuxFrame, rpcId?: string): void {
+    for (const conn of [...this.muxConns]) conn.feed({ kind: 'frame', envelope: { rpcId: RpcId(rpcId ?? `push-${nextRpc++}`), payload: frame } })
+  }
+
+  pushHost(frame: HostFrame, rpcId?: string): void {
+    for (const conn of [...this.hostConns]) conn.feed({ kind: 'frame', envelope: { rpcId: RpcId(rpcId ?? `push-${nextRpc++}`), payload: frame } })
+  }
+
+  /** End (clean close) or fail (throw) every open stream — reconnect-path material. */
+  endStreams(): void {
+    for (const conn of [...this.muxConns, ...this.hostConns]) conn.feed({ kind: 'end' })
+  }
+
+  failStreams(error: unknown): void {
+    for (const conn of [...this.muxConns, ...this.hostConns]) conn.feed({ kind: 'fail', error })
+  }
+
+  get openMuxCount(): number {
+    return this.muxConns.length
+  }
+
+  callsOf(method: string): unknown[] {
+    return this.calls.filter(c => c.method === method).map(c => c.payload)
+  }
+
+  private record<T>(method: string, payload: unknown, response: Promise<T>): Promise<T> {
+    this.calls.push({ method, payload })
+    return response
+  }
+
+  private async *openStream<F>(registry: StreamConn<F>[], signal: AbortSignal, onOpen?: () => void): AsyncGenerator<RpcRequest<F>> {
+    const inbox: StreamItem<F>[] = []
+    let wake: (() => void) | null = null
+    const conn: StreamConn<F> = {
+      feed: (item) => {
+        inbox.push(item)
+        wake?.()
+      },
+    }
+    registry.push(conn)
+    if (this.holdStreamOpen && onOpen !== undefined) this.heldOpens.push(onOpen)
+    else if (!this.suppressStreamOpen) onOpen?.()
+    try {
+      while (!signal.aborted) {
+        while (inbox.length > 0) {
+          const item = inbox.shift() as StreamItem<F>
+          if (item.kind === 'end') return
+          if (item.kind === 'fail') throw item.error
+          yield item.envelope
+        }
+        await new Promise<void>((resolve) => {
+          wake = resolve
+          signal.addEventListener('abort', () => { resolve() }, { once: true })
+        })
+        wake = null
+      }
+    } finally {
+      registry.splice(registry.indexOf(conn), 1)
+    }
+  }
+}

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

@@ -0,0 +1,338 @@
+/**
+ * Fixture impl semantics: the demo data source must honor the same contract
+ * shapes as the real host (paging boundaries, rpcId echo, replay lifecycle,
+ * baseline replay, timing hooks) — this is the vitest-side drift detector for
+ * the hand-written fixture/host parallel implementations.
+ */
+
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import type { SessionId } from '../src/client/api.ts'
+import { RpcId } from '../src/client/api.ts'
+import type { HostFrame, MuxFrame, RpcMessage, RpcRequest } from '../src/client/api.ts'
+import { FixtureApiClient, createFixtureApi } from '../src/client/fixture.ts'
+
+const sid = (id: string): SessionId => id as SessionId
+const req = <P>(payload: P): RpcRequest<P> => ({ rpcId: RpcId(`t-${Math.abs(Math.sin(reqCount++)).toString(36).slice(2, 10)}`), payload })
+let reqCount = 0
+
+interface TimingHooks {
+  setHistoryDelay(ms: number): void
+  failNextHistory(): void
+  appendUser(id: string, msg: string): void
+  appendSilent(id: string, msg: string): void
+  breakStreams(): void
+}
+const timing = (): TimingHooks => (globalThis as Record<string, unknown>).__fxTiming as TimingHooks
+
+/** Collect stream frames until the predicate or a soft cap; abort ends the stream. */
+async function collect<F>(stream: AsyncIterable<RpcRequest<F>>, abort: AbortController, done: (frames: F[]) => boolean): Promise<F[]> {
+  const frames: F[] = []
+  for await (const envelope of stream) {
+    frames.push(envelope.payload)
+    if (done(frames) || frames.length > 500) {
+      abort.abort()
+      break
+    }
+  }
+  return frames
+}
+
+describe('createFixtureApi', () => {
+  it('serves the session list sorted by updatedAt desc and echoes rpcIds on every unary', async () => {
+    const api = createFixtureApi()
+    const request = req({})
+    const response = await api.sessions.list(request)
+    expect(response.rpcId).toBe(request.rpcId)
+    if (!response.result.ok) throw new Error('list failed')
+    expect(response.result.value.items.map(s => s.sessionId)).toEqual(['fx-alpha', 'fx-beta', 'fx-gamma'])
+    expect(response.result.value.items[1]?.parentSessionId).toBe('fx-alpha') // lineage material
+  })
+
+  it('pages history backwards on message-boundary cuts with seq-contiguous stitching', async () => {
+    const api = createFixtureApi()
+    const tail = await api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 10 }))
+    if (!tail.result.ok) throw new Error('history failed')
+    const tailPage = tail.result.value
+    expect(tailPage.hasMore).toBe(true)
+    expect(tailPage.events[0]?.event.type).toBe('turn/start') // cut lands on a turn boundary
+    const boundary = tailPage.events[0]?.event.seq ?? 0
+    expect(boundary).toBeGreaterThan(0)
+    const older = await api.sessions.history(req({ sessionId: sid('fx-alpha'), beforeSeq: boundary, maxMessages: 10 }))
+    if (!older.result.ok) throw new Error('older failed')
+    const olderTail = older.result.value.events.at(-1)?.event
+    expect((olderTail?.seq ?? -1) + 1).toBe(boundary) // pages stitch with no hole/overlap
+    // Out-of-range beforeSeq clamps instead of exploding.
+    const clamped = await api.sessions.history(req({ sessionId: sid('fx-alpha'), beforeSeq: -5, maxMessages: 10 }))
+    if (!clamped.result.ok) throw new Error('clamped failed')
+    expect(clamped.result.value.events).toEqual([])
+    // Unknown session: empty page, not an error (history of a bare id).
+    const empty = await api.sessions.history(req({ sessionId: sid('no-such'), maxMessages: 10 }))
+    if (!empty.result.ok) throw new Error('empty failed')
+    expect(empty.result.value).toEqual({ events: [], hasMore: false })
+  })
+
+  it('create adds a session and pushes host/session-added to open host streams', async () => {
+    const api = createFixtureApi()
+    const abort = new AbortController()
+    const seen: HostFrame[] = []
+    const consuming = (async () => {
+      for await (const envelope of api.events.host(req({}), abort.signal)) {
+        seen.push(envelope.payload)
+        if (seen.length >= 1) abort.abort()
+      }
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10)) // let the stream register
+    const created = await api.sessions.create(req({}))
+    if (!created.result.ok) throw new Error('create failed')
+    await consuming
+    if (!created.result.ok) throw new Error('create failed')
+    const createdId = created.result.value.sessionId
+    expect(seen).toEqual([{ type: 'host/session-added', sessionId: createdId }])
+    const list = await api.sessions.list(req({}))
+    if (!list.result.ok) throw new Error('list failed')
+    expect(list.result.value.items.some(s => s.sessionId === createdId)).toBe(true)
+  })
+
+  it('prompt replays a full streamed turn and cancel mid-replay freezes with (已中断)', async () => {
+    const api = createFixtureApi()
+    const created = await api.sessions.create(req({}))
+    if (!created.result.ok) throw new Error('create failed')
+    const id = created.result.value.sessionId
+    const abort = new AbortController()
+    const frames: MuxFrame[] = []
+    const consuming = (async () => {
+      for await (const envelope of api.events.mux(req({}), abort.signal)) {
+        frames.push(envelope.payload)
+        const last = envelope.payload
+        if (last.type === 'session/event' && last.event.type === 'turn/end') {
+          abort.abort()
+        }
+      }
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10))
+    // Unknown session → session-not-found with the id echoed in details.
+    const missing = await api.sessions.prompt(req({ sessionId: sid('ghost'), mode: 'queue' as const, content: [{ type: 'text' as const, text: 'x' }] }))
+    expect(missing.result).toMatchObject({ ok: false, error: { code: 'session-not-found', details: { sessionId: 'ghost' } } })
+    // Real prompt: replay starts (running flips true), cancel freezes it.
+    const accepted = await api.sessions.prompt(req({ sessionId: id, mode: 'queue' as const, content: [{ type: 'text' as const, text: '取消我' }] }))
+    expect(accepted.result).toMatchObject({ ok: true, value: { accepted: true } })
+    await new Promise(resolve => setTimeout(resolve, 120)) // a couple of typewriter ticks
+    await api.sessions.cancel(req({ sessionId: id }))
+    await consuming
+    const types = frames.filter((f): f is Extract<MuxFrame, { type: 'session/event' }> => f.type === 'session/event').map(f => f.event.type)
+    expect(types).toContain('turn/start')
+    expect(types).toContain('user/message')
+    expect(types).toContain('assistant/chunk')
+    expect(types).toContain('assistant/message')
+    expect(types.at(-1)).toBe('turn/end')
+    const finalize = frames.find((f): f is Extract<MuxFrame, { type: 'session/event' }> => f.type === 'session/event' && f.event.type === 'assistant/message')
+    expect(JSON.stringify(finalize?.event.data)).toContain('（已中断）')
+    // Idle cancel: no replay in flight, must not explode; running flips false.
+    const idleCancel = await api.sessions.cancel(req({ sessionId: id }))
+    expect(idleCancel.result).toMatchObject({ ok: true })
+  })
+
+  it('steer during a replay inserts a steering message and the replay continues to completion', async () => {
+    const api = createFixtureApi()
+    const created = await api.sessions.create(req({}))
+    if (!created.result.ok) throw new Error('create failed')
+    const id = created.result.value.sessionId
+    const abort = new AbortController()
+    const framesPromise = collect<MuxFrame>(api.events.mux(req({}), abort.signal), abort,
+      frames => frames.some(f => f.type === 'session/event' && f.event.type === 'turn/end'))
+    await new Promise(resolve => setTimeout(resolve, 10))
+    await api.sessions.prompt(req({ sessionId: id, mode: 'queue' as const, content: [{ type: 'text' as const, text: '短' }] }))
+    await api.sessions.prompt(req({ sessionId: id, mode: 'steer' as const, content: [{ type: 'text' as const, text: '插话' }] }))
+    const frames = await framesPromise
+    const types = frames.filter((f): f is Extract<MuxFrame, { type: 'session/event' }> => f.type === 'session/event').map(f => f.event.type)
+    expect(types).toContain('steering/message')
+    expect(types.at(-1)).toBe('turn/end') // steer did not restart the turn
+  })
+
+  it('mux open replays the baseline: subscribed for running sessions + the resident approval with a stable rpcId', async () => {
+    const api = createFixtureApi()
+    const openOnce = async (): Promise<RpcRequest<MuxFrame>[]> => {
+      const abort = new AbortController()
+      const envelopes: RpcRequest<MuxFrame>[] = []
+      for await (const envelope of api.events.mux(req({}), abort.signal)) {
+        envelopes.push(envelope)
+        if (envelopes.length >= 2) abort.abort()
+      }
+      return envelopes
+    }
+    const first = await openOnce()
+    const second = await openOnce()
+    expect(first[0]?.payload).toMatchObject({ type: 'session/subscribed', sessionId: 'fx-alpha' })
+    expect((first[0]?.payload as { lastSeq: number }).lastSeq).toBeGreaterThan(0)
+    expect(first[1]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
+    expect(second[1]?.rpcId).toBe(first[1]?.rpcId) // stable rpcId across replays (host replay semantics)
+  })
+
+  it('steer with no replay in flight falls through to a fresh queued turn; non-text blocks stringify empty', async () => {
+    const api = createFixtureApi()
+    const abort = new AbortController()
+    const framesPromise = collect<MuxFrame>(api.events.mux(req({}), abort.signal), abort,
+      frames => frames.some(f => f.type === 'session/event' && f.event.type === 'turn/end'))
+    await new Promise(resolve => setTimeout(resolve, 10))
+    const created = await api.sessions.create(req({}))
+    if (!created.result.ok) throw new Error('create failed')
+    // steer while idle + a non-text content block (covers the '' arm of the text join).
+    await api.sessions.prompt(req({
+      sessionId: created.result.value.sessionId, mode: 'steer' as const,
+      content: [{ type: 'text' as const, text: '短' }, { type: 'image', data: 'x' } as never],
+    }))
+    const frames = await framesPromise
+    const types = frames.filter((f): f is Extract<MuxFrame, { type: 'session/event' }> => f.type === 'session/event').map(f => f.event.type)
+    expect(types[0]).toBe('turn/start') // idle steer degraded to a queued turn, not a steering insert
+  })
+
+  it('gamma interval flip emits host/session-status and a running log-less session subscribes at lastSeq -1', async () => {
+    vi.useFakeTimers()
+    try {
+      const api = createFixtureApi()
+      const abort = new AbortController()
+      const hostSeen: HostFrame[] = []
+      const consuming = (async () => {
+        for await (const envelope of api.events.host(req({}), abort.signal)) hostSeen.push(envelope.payload)
+      })()
+      await vi.advanceTimersByTimeAsync(5001) // interval fires: fx-gamma flips running=true (no log exists)
+      expect(hostSeen).toContainEqual({ type: 'host/session-status', sessionId: sid('fx-gamma'), running: true })
+      // A mux stream opened now sees gamma in the baseline with lastSeq = -1 (empty log arm).
+      const mabort = new AbortController()
+      const baseline: MuxFrame[] = []
+      const muxConsuming = (async () => {
+        for await (const envelope of api.events.mux(req({}), mabort.signal)) {
+          baseline.push(envelope.payload)
+          if (baseline.length >= 3) mabort.abort()
+        }
+      })()
+      await vi.advanceTimersByTimeAsync(10)
+      mabort.abort()
+      await muxConsuming
+      expect(baseline).toContainEqual({ type: 'session/subscribed', sessionId: sid('fx-gamma'), lastSeq: -1 })
+      abort.abort()
+      await vi.advanceTimersByTimeAsync(10)
+      await consuming
+    } finally {
+      vi.useRealTimers()
+    }
+  })
+
+  it('respond is a typed stub: always not-pending', async () => {
+    const api = createFixtureApi()
+    expect(await api.respond({ type: 'client-response', rpcId: RpcId('x'), result: { ok: true, value: {} } })).toEqual({ accepted: false, reason: 'not-pending' })
+  })
+
+  it('describe answers the fixture identity', async () => {
+    const api = createFixtureApi()
+    const response = await api.host.describe(req({}))
+    expect(response.result).toMatchObject({ ok: true, value: { version: '0.0.0-fixture', attachedSessions: 1 } })
+  })
+
+  it('timing hooks: history delay + one-shot failure, silent append, and breakStreams end open generators', async () => {
+    const api = createFixtureApi()
+    const hooks = timing()
+    // One-shot transport failure after transit delay.
+    hooks.setHistoryDelay(5)
+    hooks.failNextHistory()
+    await expect(api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 5 }))).rejects.toThrow(/simulated history transport failure/)
+    hooks.setHistoryDelay(0)
+    // The failure was one-shot: the next call succeeds.
+    const ok = await api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 5 }))
+    expect(ok.result.ok).toBe(true)
+    // appendUser emits on the mux stream; appendSilent only lands in the log (lost frame).
+    const abort = new AbortController()
+    const seen: MuxFrame[] = []
+    const consuming = (async () => {
+      for await (const envelope of api.events.mux(req({}), abort.signal)) seen.push(envelope.payload)
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10))
+    hooks.appendSilent('fx-alpha', '静默丢帧')
+    hooks.appendUser('fx-alpha', '正常直播')
+    await vi.waitFor(() => {
+      expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('正常直播'))).toBe(true)
+    })
+    expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('静默丢帧'))).toBe(false)
+    // But history serves the silent event (the client's repull finds it).
+    const repull = await api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 5 }))
+    if (!repull.result.ok) throw new Error('repull failed')
+    expect(JSON.stringify(repull.result.value.events)).toContain('静默丢帧')
+    // breakStreams force-ends BOTH stream kinds without the client abort.
+    const habort = new AbortController()
+    const hostConsuming = (async () => {
+      for await (const _ of api.events.host(req({}), habort.signal)) { /* drain */ }
+    })()
+    await new Promise(resolve => setTimeout(resolve, 10))
+    hooks.breakStreams()
+    await consuming // returns because the stream broke, not because we aborted
+    await hostConsuming
+    expect(abort.signal.aborted).toBe(false)
+    expect(habort.signal.aborted).toBe(false)
+  })
+})
+
+describe('FixtureApiClient (protocol-level fake carrier)', () => {
+  afterEach(() => {
+    vi.restoreAllMocks()
+  })
+
+  it('doFetch is an unreachable tripwire (all protocol paths overridden)', () => {
+    const client = new FixtureApiClient()
+    // Protected at compile time only; reach it directly to pin the tripwire message.
+    expect(() => (client as unknown as { doFetch(): Promise<Response> }).doFetch()).toThrow(/doFetch must be unreachable/)
+  })
+
+  it('mints request ids, taps all four full forms, and never touches doFetch', async () => {
+    const client = new FixtureApiClient()
+    const tapped: RpcMessage[] = []
+    client.subscribeEnvelopes(batch => tapped.push(...batch))
+    const response = await client.sessions.list({})
+    expect(response.result.ok).toBe(true)
+    await client.respond({ type: 'client-response', rpcId: RpcId('r-x'), result: { ok: true, value: {} } })
+    await vi.waitFor(() => {
+      const kinds = tapped.map(m => m.type)
+      expect(kinds).toContain('client-request')
+      expect(kinds).toContain('server-response')
+      expect(kinds).toContain('client-response')
+    })
+    const request = tapped.find(m => m.type === 'client-request')
+    const reply = tapped.find(m => m.type === 'server-response')
+    expect(request?.rpcId).toBe(reply?.rpcId) // echo discipline holds through the fake carrier
+  })
+
+  it('covers the whole unary dispatch table', async () => {
+    const client = new FixtureApiClient()
+    const created = await client.sessions.create({})
+    if (!created.result.ok) throw new Error('create failed')
+    const id = created.result.value.sessionId
+    expect((await client.sessions.history({ sessionId: id })).result.ok).toBe(true)
+    expect((await client.sessions.prompt({ sessionId: id, mode: 'queue', content: [{ type: 'text', text: '嗨' }] })).result.ok).toBe(true)
+    expect((await client.sessions.cancel({ sessionId: id })).result.ok).toBe(true)
+    expect((await client.host.describe({})).result.ok).toBe(true)
+  })
+
+  it('fires onOpen at stream-iteration start and taps server-request full forms', async () => {
+    const client = new FixtureApiClient()
+    const tapped: RpcMessage[] = []
+    client.subscribeEnvelopes(batch => tapped.push(...batch))
+    const order: string[] = []
+    const abort = new AbortController()
+    for await (const envelope of client.events.mux({}, abort.signal, () => order.push('open'))) {
+      order.push(envelope.payload.type)
+      abort.abort()
+    }
+    expect(order[0]).toBe('open')
+    expect(order[1]).toBe('session/subscribed')
+    await vi.waitFor(() => {
+      expect(tapped.some(m => m.type === 'server-request')).toBe(true)
+    })
+    // Host stream side of the pair (same tap path).
+    const habort = new AbortController()
+    const hostOrder: string[] = []
+    const hostIterator = client.events.host({}, habort.signal, () => hostOrder.push('open'))[Symbol.asyncIterator]()
+    const raced = await Promise.race([hostIterator.next(), new Promise<'idle'>(resolve => setTimeout(() => { resolve('idle') }, 50))])
+    expect(hostOrder).toEqual(['open']) // established even though the host stream stays silent
+    habort.abort()
+    if (raced === 'idle') await hostIterator.return?.(undefined)
+  })
+})

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

@@ -0,0 +1,10 @@
+/** Node half: the empty host apply (Loader governance + dshClient discovery placeholder). */
+import { describe, expect, it } from 'vitest'
+import { apply } from '../src/index.ts'
+
+describe('node half', () => {
+  it('apply is a no-op host placeholder', () => {
+    apply(undefined)
+    expect(true).toBe(true) // reaching here without throw is the contract
+  })
+})

packages/client/connection/tsconfig.json

@@ -0,0 +1,42 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types",
+    "lib": [
+      "ES2024",
+      "DOM",
+      "DOM.Iterable"
+    ],
+    "types": []
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../llm/llm"
+    },
+    {
+      "path": "../../core/session"
+    },
+    {
+      "path": "../../util/brand"
+    },
+    {
+      "path": "../../host/apiproxy"
+    },
+    {
+      "path": "../../ui/user-approval"
+    },
+    {
+      "path": "../../ui/user-interaction"
+    },
+    {
+      "path": "../../support/invariants"
+    }
+  ],
+  "exclude": [
+    "**/*.legacy.*"
+  ]
+}

packages/client/connection/tsdown.config.ts

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