Merge remote-tracking branch 'origin/master' into codex/status-bar-token-metrics

# Conflicts: # docs/cordis-catalog/events.md # docs/event-producer-consumer.md # packages/client/runtime/src/client/sessions/conversation.ts # packages/client/runtime/src/client/sessions/session.ts # packages/client/runtime/tests/fake-api.ts # packages/client/runtime/tests/session.spec.ts # packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx # packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx # packages/client/ui-conversation/tests/chat-view.spec.tsx # packages/client/ui-conversation/tests/gate-branch-tails.spec.tsx # packages/client/ui-conversation/tests/queue-dock.spec.tsx # packages/core/agent-loop/README.i18n.yaml # packages/core/agent/README.i18n.yaml # packages/host/apiproxy/README.i18n.yaml # packages/host/apiproxy/src/api-proxy.ts # packages/host/apiproxy/src/api/events.schema.ts # packages/host/apiproxy/src/api/events.ts # packages/host/apiproxy/src/api/index.ts # packages/host/apiproxy/src/api/sessions.schema.ts # packages/host/apiproxy/src/api/sessions.ts # packages/host/apiproxy/tests/rpc-schemas.spec.ts
2026-07-28 19:34:30 +08:00
parent e6ce6abd7d b1292df3fa
commit e466c66ee3
227 changed files with 5531 additions and 776 deletions
--- a/packages/client/connection/package.json
+++ b/packages/client/connection/package.json
@@ -30,6 +30,7 @@
  "license": "BSD-3-Clause",
  "dependencies": {
    "@deepseek-ai/dsh-host-apiproxy": "workspace:^",
+    "@deepseek-ai/dsh-commands": "workspace:^",
    "@deepseek-ai/dsh-llm": "workspace:^",
    "@deepseek-ai/dsh-session": "workspace:^",
    "@deepseek-ai/dsh-tools": "workspace:^"
--- a/packages/client/connection/src/client/api.ts
+++ b/packages/client/connection/src/client/api.ts
@@ -9,9 +9,9 @@ export type {
  ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
  ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
  WorkspaceApi, WorkspaceId, WorkspaceView,
-  CommandsApi, CommandDescriptor, CommandExecuteResult, SkillsApi, SkillEntry,
+  CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
  ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
-  ModelReasoningEffort, ModelTarget, SessionMetrics, SessionModels,
+  ModelReasoningEffort, ModelTarget, SessionMetrics, SessionModels, SessionProjectionsBlock,
 } from '@deepseek-ai/dsh-host-apiproxy/api'
 export type { ToolCallView, ToolResultView } from '@deepseek-ai/dsh-tools/presentation'
 export type {
--- a/packages/client/connection/src/client/fixture.ts
+++ b/packages/client/connection/src/client/fixture.ts
@@ -7,6 +7,9 @@

 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type { SessionEvent, SessionId, TodoItem } from '@deepseek-ai/dsh-session/types'
+// Type-only: the brand constructor is host-side; the fixture casts at its
+// wire-fabrication boundary (the schema layer's one-cast-point posture).
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type {
  ApiProxy, ClientRequest, ClientResponse, HistoryEntry, HostFrame, MuxFrame, RpcReceipt,
  ModelTarget, RpcRequest, RpcResponse, RpcResult, ServerRequest, ServerResponse, SessionSummary,
@@ -271,18 +274,27 @@ function viewFor(event: SessionEvent, log: readonly SessionEvent[]): ToolEventVi
  return undefined
 }

-/** Fold the latest fixture title into the host's control-frame projection. */
-function titleFrameOf(id: SessionId, log: readonly SessionEvent[]): Extract<MuxFrame, { type: 'session/title' }> | undefined {
-  const event = log.findLast(item => (item as { type: string }).type === 'session/title')
-  if (event === undefined) return undefined
-  const titleEvent = event as unknown as { seq: number; time: number; data: { title: string } }
-  return {
-    type: 'session/title',
-    sessionId: id,
-    title: titleEvent.data.title,
-    eventSeq: titleEvent.seq,
-    updatedAt: titleEvent.time,
+/** Fixture parallel of the host's projection units: whole current values per key over the full log. */
+function projectionValuesOf(log: readonly SessionEvent[]): Record<string, unknown> {
+  const values: Record<string, unknown> = {}
+  const titleEvent = log.findLast(item => (item as { type: string }).type === 'session/title')
+  if (titleEvent !== undefined) {
+    values['title'] = (titleEvent as unknown as { data: { title: string } }).data.title
  }
+  const todos = backscanTodos(log)
+  if (todos !== undefined) values['todos'] = todos
+  return values
+}
+
+/** Host push-frame parallel: emit one session/projection frame per key the given event advanced. */
+function projectionFramesOf(id: SessionId, log: readonly SessionEvent[], event: SessionEvent): Extract<MuxFrame, { type: 'session/projection' }>[] {
+  const type = (event as { type: string }).type
+  const key = type === 'session/title' ? 'title' : type === 'todo/write' ? 'todos' : undefined
+  if (key === undefined) return []
+  const values = projectionValuesOf(log)
+  /* v8 ignore next -- the advancing event is in the log, so its key always has a value. */
+  if (!Object.hasOwn(values, key)) return []
+  return [{ type: 'session/projection', sessionId: id, key, value: values[key], seq: event.seq }]
 }

 /**
@@ -512,10 +524,8 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
    emitMux(view === undefined
      ? { type: 'session/event', sessionId: id, event }
      : { type: 'session/event', sessionId: id, event, view })
-    if ((event as { type: string }).type === 'session/title') {
-      // The raw title is already in this log, so the latest-title fold must find it.
-      emitMux(titleFrameOf(id, log) as Extract<MuxFrame, { type: 'session/title' }>)
-    }
+    // Host eager-drive parallel: a unit-advancing event pushes its finished value.
+    for (const frame of projectionFramesOf(id, log, event)) emitMux(frame)
  }

  /** At most one in-flight replay per session; cancel clears it. */
@@ -668,14 +678,18 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
        const log = logs.get(request.payload.sessionId) ?? []
        // Snapshot at request time, deliver after the transit delay (mirrors a real host under latency).
        const page = pageOf(log, request.payload.beforeSeq, request.payload.maxMessages ?? 50)
-        // Tail page carries the session-level todo projection (host parallel: full-log backscan).
-        const todos = request.payload.beforeSeq === undefined ? backscanTodos(log) : undefined
+        // Tail page carries the projections block (host parallel: one consistent
+        // cut over the registered units; asOfSeq = window tail seq, -1 on an
+        // empty log — the host's session.seq-1 convention).
+        const projections = request.payload.beforeSeq === undefined
+          ? { asOfSeq: log.length - 1, values: projectionValuesOf(log) }
+          : undefined
        const doomed = failNextHistory
        failNextHistory = false
        const delay = historyDelayMs
        if (delay > 0) await new Promise(resolve => setTimeout(resolve, delay))
        if (doomed) throw new Error('fixture: simulated history transport failure')
-        return ok(request, { ...page, ...todos === undefined ? {} : { todos } })
+        return ok(request, { ...page, ...projections === undefined ? {} : { projections } })
      },
      models: request => ok(request, {
        current: modelTargets.get(request.payload.sessionId)
@@ -880,25 +894,29 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
          ],
        })
      },
+      // Pure admission, mirroring the host: an admitted command logs the
+      // command/run + command/done lifecycle pair (mux-broadcast by append),
+      // and the response only reports resolution.
      execute: (request) => {
        const missing = requireSession(request)
        if (missing !== undefined) return missing
-        const line = request.payload.line.trim()
-        const match = /^\/(\S+)(?:\s+(.*))?$/.exec(line)
+        const id = request.payload.sessionId
+        // Structured split mirroring the host parser: name + verbatim rawInput
+        // (separator whitespace included) — the run payload carries no line.
+        const match = /^\/(\S+)((?:\s.*)?)$/.exec(request.payload.line.trim())
        const name = match?.[1]
-        if (name === 'compact' || name === 'echo') {
-          return ok(request, {
-            matched: true as const,
-            result: { kind: 'success' as const, text: name === 'echo' ? (match?.[2] ?? '') : 'fixture：已压缩（假动作）' },
-          })
+        const args = match?.[2] ?? ''
+        const outcomes: Record<string, string> = {
+          compact: 'fixture：已压缩（假动作）',
+          echo: args.trim(),
+          'goal-fixture': `fixture：goal 已设置（${id}）`,
        }
-        if (name === 'goal-fixture') {
-          return ok(request, {
-            matched: true as const,
-            result: { kind: 'success' as const, text: `fixture：goal 已设置（${request.payload.sessionId}）` },
-          })
-        }
-        return ok(request, { matched: false as const })
+        const text = name === undefined ? undefined : outcomes[name]
+        if (name === undefined || text === undefined) return ok(request, { matched: false as const })
+        const commandId = `fx-cmd-${logOf(id).length}` as CommandId
+        append(id, { type: 'command/run', data: { commandId, name, args, source: { kind: 'user' } } })
+        append(id, { type: 'command/done', data: { commandId, kind: 'success', ...text === '' ? {} : { text } } })
+        return ok(request, { matched: true as const, commandId })
      },
    },
    skills: {
@@ -921,9 +939,13 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
        // Open baseline: subscribed sessions + pending interactions replayed with stable rpcIds.
        for (const s of sessions) {
          if (!s.running) continue
-          conn.push({ rpcId: mint(), payload: { type: 'session/subscribed', sessionId: s.sessionId, lastSeq: (logs.get(s.sessionId)?.length ?? 0) - 1 } })
-          const title = titleFrameOf(s.sessionId, logs.get(s.sessionId) ?? [])
-          if (title !== undefined) conn.push({ rpcId: mint(), payload: title })
+          const log = logs.get(s.sessionId) ?? []
+          conn.push({ rpcId: mint(), payload: { type: 'session/subscribed', sessionId: s.sessionId, lastSeq: log.length - 1 } })
+          // Post-subscribe projection baseline (host parallel: recomputed unit values ride push frames).
+          const values = projectionValuesOf(log)
+          for (const key of Object.keys(values)) {
+            conn.push({ rpcId: mint(), payload: { type: 'session/projection', sessionId: s.sessionId, key, value: values[key], seq: log.length - 1 } })
+          }
        }
        conn.push({
          rpcId: pendingApprovalRpcId,
--- a/packages/client/connection/src/client/index.ts
+++ b/packages/client/connection/src/client/index.ts
@@ -14,9 +14,9 @@ export type {
  ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
  ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
  ToolCallView, ToolResultView, WorkspaceApi, WorkspaceId, WorkspaceView,
-  CommandsApi, CommandDescriptor, CommandExecuteResult, SkillsApi, SkillEntry,
+  CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
  ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
-  ModelReasoningEffort, ModelTarget, SessionMetrics, SessionModels,
+  ModelReasoningEffort, ModelTarget, SessionMetrics, SessionModels, SessionProjectionsBlock,
  RpcRequest, RpcResponse, RpcResult, RpcError, RpcErrorCode,
  ClientRequest, ServerResponse, ServerRequest, ClientResponse, RpcMessage, RpcReceipt,
  IApiClient, SessionId, SessionEvent, ContentBlock, StreamChunk,
--- a/packages/client/connection/tests/fake-api.ts
+++ b/packages/client/connection/tests/fake-api.ts
@@ -1,8 +1,9 @@
 // Test-local programmable IApiClient fake (NOT the fixture: fixture is a demo
 // data source on a real clock; behavior tests need per-case responses and
 // deferred-controlled timing). Streams are hand pumps: pushMux/pushHost.
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type {
-  CommandDescriptor, CommandExecuteResult, HostFrame, IApiClient, ModelTarget, MuxFrame,
+  CommandDescriptor, HostFrame, IApiClient, ModelTarget, MuxFrame,
  RpcRequest, RpcResponse, SessionId, SessionModels, SkillEntry,
 } from '../src/client/api.ts'
 import { RpcId } from '../src/client/api.ts'
@@ -110,10 +111,12 @@ export class FakeApiClient implements IApiClient {

  // Payloads stay `unknown` (lint-lane note above); response rows are the real
  // wire shapes so cases can program catalogs and skill lists without casts.
-  onCommandList: (payload: unknown) => Promise<RpcResponse<{ commands: CommandDescriptor[] }>> = () => Promise.resolve(ok({ commands: [] }))
-  onCommandExecute: (payload: unknown) => Promise<RpcResponse<{ matched: boolean; result?: CommandExecuteResult }>> =
-    () => Promise.resolve(ok({ matched: false }))
-  onSkillList: (payload: unknown) => Promise<RpcResponse<{ skills: SkillEntry[] }>> = () => Promise.resolve(ok({ skills: [] }))
+  onCommandList: (payload: unknown) => Promise<RpcResponse<{ commands: CommandDescriptor[] }>>
+    = () => Promise.resolve(ok({ commands: [] }))
+  onCommandExecute: (payload: unknown) => Promise<RpcResponse<{ matched: boolean; commandId?: CommandId }>>
+    = () => Promise.resolve(ok({ matched: false }))
+  onSkillList: (payload: unknown) => Promise<RpcResponse<{ skills: SkillEntry[] }>>
+    = () => Promise.resolve(ok({ skills: [] }))

  readonly commands: IApiClient['commands'] = {
    list: (payload: unknown) => this.record('command.list', payload, this.onCommandList(payload)),
--- a/packages/client/connection/tests/fixture-commands.spec.ts
+++ b/packages/client/connection/tests/fixture-commands.spec.ts
@@ -36,20 +36,37 @@ describe('createFixtureApi commands/skills', () => {
    expect(response.result).toMatchObject({ ok: false, error: { code: 'session-not-found' } })
  })

-  it('executes a known command line and reports matched with a result', async () => {
+  it('executes a known command line: pure admission plus a mux-broadcast lifecycle pair', async () => {
    const api = createFixtureApi()
+    const frames: unknown[] = []
+    const abort = new AbortController()
+    const stream = api.events.mux(req({}), abort.signal)
+    const pump = (async () => {
+      for await (const frame of stream) {
+        frames.push(frame.payload)
+        if (frames.filter(f => (f as { type: string }).type === 'session/event').length >= 2) abort.abort()
+      }
+    })()
    const response = await api.commands.execute(req({ sessionId: sid('fx-alpha'), line: '/echo hello world' }), signal)
    if (!response.result.ok) throw new Error('execute failed')
-    expect(response.result.value.matched).toBe(true)
-    expect(response.result.value.result).toEqual({ kind: 'success', text: 'hello world' })
+    expect(response.result.value).toMatchObject({ matched: true })
+    expect(response.result.value.commandId).toBeTruthy()
+    await pump
+    const events = frames
+      .filter((f): f is { type: string; event: { type: string; data: Record<string, unknown> } } => (f as { type: string }).type === 'session/event')
+      .map(f => f.event)
+    expect(events).toMatchObject([
+      { type: 'command/run', data: { name: 'echo', args: ' hello world', source: { kind: 'user' } } },
+      { type: 'command/done', data: { kind: 'success', text: 'hello world' } },
+    ])
+    expect(events[0]?.data.commandId).toBe(events[1]?.data.commandId)
  })

-  it('addresses execute to the session (result text carries the id)', async () => {
+  it('addresses execute to the session; an unknown session errs', async () => {
    const api = createFixtureApi()
    const hit = await api.commands.execute(req({ sessionId: sid('fx-alpha'), line: '/goal-fixture ship' }), signal)
    if (!hit.result.ok) throw new Error('execute failed')
    expect(hit.result.value.matched).toBe(true)
-    expect(hit.result.value.result?.text).toContain('fx-alpha')

    const missing = await api.commands.execute(req({ sessionId: sid('fx-nope'), line: '/goal-fixture ship' }), signal)
    expect(missing.result).toMatchObject({ ok: false, error: { code: 'session-not-found' } })
@@ -60,8 +77,8 @@ describe('createFixtureApi commands/skills', () => {
    for (const line of ['/nope', 'plain text', '/']) {
      const response = await api.commands.execute(req({ sessionId: sid('fx-alpha'), line }), signal)
      if (!response.result.ok) throw new Error('execute failed')
-      expect(response.result.value.matched).toBe(false)
-      expect(response.result.value.result).toBeUndefined()
+      // Pure admission value: the matched bit is the whole response shape.
+      expect(response.result.value).toEqual({ matched: false })
    }
  })

--- a/packages/client/connection/tests/fixture.spec.ts
+++ b/packages/client/connection/tests/fixture.spec.ts
@@ -65,13 +65,11 @@ describe('createFixtureApi', () => {
    const clamped = await api.sessions.history(req({ sessionId: sid('fx-alpha'), beforeSeq: -5, maxMessages: 10 }))
    if (!clamped.result.ok) throw new Error('clamped failed')
    expect(clamped.result.value.events).toEqual([])
-    // Unknown session: empty page, not an error (history of a bare id).
+    // Unknown session: empty page, not an error (history of a bare id). The
+    // tail block still rides it — empty-log cut at -1, the host convention.
    const empty = await api.sessions.history(req({ sessionId: sid('no-such'), maxMessages: 10 }))
    if (!empty.result.ok) throw new Error('empty failed')
-    expect(empty.result.value).toEqual({
-      events: [],
-      hasMore: false,
-    })
+    expect(empty.result.value).toEqual({ events: [], hasMore: false, projections: { asOfSeq: -1, values: {} } })
  })

  it('serves grouped models and keeps a selected target for later history and fixture requests', async () => {
@@ -213,11 +211,13 @@ describe('createFixtureApi', () => {
    const second = await openOnce()
    expect(first[0]?.payload).toMatchObject({ type: 'session/subscribed', sessionId: 'fx-alpha' })
    expect((first[0]?.payload as { lastSeq: number }).lastSeq).toBeGreaterThan(0)
-    expect(first[1]?.payload).toMatchObject({ type: 'session/title', sessionId: 'fx-alpha', title: 'Fixture 历史会话' })
-    expect(first[2]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
-    expect(second[2]?.rpcId).toBe(first[2]?.rpcId) // stable rpcId across replays (host replay semantics)
-    expect(first[3]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
-    expect(second[3]?.rpcId).toBe(first[3]?.rpcId)
+    // Projection baseline frames follow the subscribed frame (title + todos units).
+    expect(first[1]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'title', value: 'Fixture 历史会话' })
+    expect(first[2]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'todos' })
+    expect(first[3]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
+    expect(second[3]?.rpcId).toBe(first[3]?.rpcId) // stable rpcId across replays (host replay semantics)
+    expect(first[4]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
+    expect(second[4]?.rpcId).toBe(first[4]?.rpcId)
  })

  it('steer with no replay in flight falls through to a fresh queued turn; non-text blocks stringify empty', async () => {
@@ -619,11 +619,11 @@ describe('createFixtureApi', () => {
    hooks.appendTitle('fx-alpha', 'Fixture 修订标题')
    await vi.waitFor(() => {
      expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('正常直播'))).toBe(true)
-      expect(seen.some(f => f.type === 'session/title' && f.title === 'Fixture 修订标题')).toBe(true)
+      expect(seen.some(f => f.type === 'session/projection' && f.key === 'title' && f.value === 'Fixture 修订标题')).toBe(true)
    })
    expect(seen.some(f => f.type === 'session/event' && JSON.stringify(f.event.data).includes('静默丢帧'))).toBe(false)
    const rawTitleIndex = seen.findIndex(f => f.type === 'session/event' && (f.event as { type: string }).type === 'session/title')
-    const titleControlIndex = seen.findIndex(f => f.type === 'session/title' && f.title === 'Fixture 修订标题')
+    const titleControlIndex = seen.findIndex(f => f.type === 'session/projection' && f.key === 'title' && f.value === 'Fixture 修订标题')
    expect(titleControlIndex).toBe(rawTitleIndex + 1)
    // But history serves the silent event (the client's repull finds it).
    const repull = await api.sessions.history(req({ sessionId: sid('fx-alpha'), maxMessages: 5 }))
--- a/packages/client/connection/tsconfig.json
+++ b/packages/client/connection/tsconfig.json
@@ -15,6 +15,9 @@
    {
      "path": "../../core/session"
    },
+    {
+      "path": "../../ui/commands"
+    },
    {
      "path": "../../util/brand"
    },
--- a/packages/client/runtime/README.i18n.yaml
+++ b/packages/client/runtime/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/runtime/README.md
-README.md: bc1149644d6112ca82c9a27912d1a58351cf84a5
-README.zh.md: 993625614061e819495b25f0851156ea20c62601
+README.md: 25370844c69aea639c9dca3d5466f5cfd1fc80c0
+README.zh.md: fde649cd2a940dcfad7bd71d9fe2314e6f28466a
--- a/packages/client/runtime/README.md
+++ b/packages/client/runtime/README.md
@@ -2,7 +2,7 @@

 English | [中文](README.zh.md)

-Client cordis boot and React-free object services: SlotsService wraps SlotCore and supplies renderer data sources; SessionsService owns Session objects, list/scope/history state; WorkspacesService depends on SessionsService and owns Workspace objects, list/actions, default-target derivation, and the New Session blank-reuse entry (`connectWorkspace`). The runtime fans the shared Host stream into both managers. Client sessions are always Host-born (Session+Agent+cwd in one `session.create`); the client holds no pre-entity session state — a session's Agent scope (the client mirror of host dsh-scope, keyed by the shared agent/session id) is born when its row enters the list mirror and dies with the prune. Contract: api-contracts v3 §4. `ConversationSnapshot` carries two Host-owned full-log projections. `todos` comes from the tail history page, survives older-page prepend, and follows live `todo/write` events. Durable `metrics` comes from tail history and live `session/metrics` frames, survives older-page prepend, and accepts only nondecreasing log and projection revisions. The Session separately retains capacity from the latest `session/model-request` observed on its current mux connection and overlays it onto metrics across ordinary usage/pressure updates. A later request replaces or clears that value, while `session/subscribed` clears both metrics ordering and capacity; reconnect, restore, and a new subscription therefore show no percentage until another request is observed. Missing metrics remain `null` rather than being inferred from the visible node window.
+Client cordis boot and React-free object services: SlotsService wraps SlotCore and supplies renderer data sources; SessionsService owns Session objects, list/scope/history state; WorkspacesService depends on SessionsService and owns Workspace objects, list/actions, default-target derivation, and the New Session blank-reuse entry (`connectWorkspace`). The runtime fans the shared Host stream into both managers. Client sessions are always Host-born (Session+Agent+cwd in one `session.create`); the client holds no pre-entity session state — a session's Agent scope (the client mirror of host dsh-scope, keyed by the shared agent/session id) is born when its row enters the list mirror and dies with the prune. Contract: api-contracts v3 §4. Generic full-log domain values such as `todos` and `title` live in the per-session projection store: history-tail `projections` seed it, `session/projection` frames update it under higher-seq-wins, and consumers read keys through `useProjection`. Durable `ConversationSnapshot.metrics` instead comes from the separate history-tail value and live `session/metrics` frames because point-in-time token-meter pressure can advance at the same durable log revision; only nondecreasing log and projection revisions are accepted. `ConversationSnapshot.modelRequestContextWindow` separately retains capacity from the latest `session/model-request` observed on the current mux connection. A later request replaces or clears that value, while `session/subscribed` clears both metrics ordering and capacity; reconnect, restore, and a new subscription therefore show no percentage until another request is observed. Missing metrics remain `null` rather than being inferred from the visible node window.

 ## Workspace and Session lists

@@ -22,7 +22,7 @@ SlotsService gives the renderer separate bare observables for `useSessions` and

 ## Session title projection

-`SessionManager` retains the latest validated `session/title` control snapshot independently of list and session-instance arrival. Newer event seqs replace older snapshots, title timestamps contribute to list recency, and a subscription baseline discards any retained title beyond its `lastSeq` before the optional folded title arrives. Explicit session removal also clears the retained title. The client-facing `SessionSummary.title` is therefore only the actual durable title; `displayTitle` is always present and falls back through the cwd basename and session id. A cold persisted session keeps that fallback until opening or resuming it causes the host to fold and project its log-backed title.
+`SessionManager` retains the generic per-session projection store independently of Session-instance arrival, so live `title` frames can update list rows before a conversation opens. A subscription baseline truncates projection rows beyond `lastSeq`; the next history-tail baseline re-seeds durable values, and explicit Session removal clears the store. The client-facing `SessionSummary.title` is therefore only the actual durable title; `displayTitle` always falls back through the cwd basename and session id while the `title` key is absent.

 ## Session model selection

--- a/packages/client/runtime/README.zh.md
+++ b/packages/client/runtime/README.zh.md
@@ -2,7 +2,7 @@

 [English](README.md) | 中文

-客户端 cordis 启动与不依赖 React 的对象服务：SlotsService 包装 SlotCore 并提供 renderer 数据源；SessionsService 拥有 Session 对象、列表／scope／history 状态；WorkspacesService 依赖 SessionsService，拥有 Workspace 对象、列表／操作、默认目标派生，以及 New Session 空会话复用入口（`connectWorkspace`）。运行时把共享 Host 流分发给两个 manager。客户端 Session 一律由 Host 出生（一次 `session.create` 同瞬产出 Session+Agent+cwd）；客户端不持有任何实体化之前的会话状态——Agent scope（host dsh-scope 的客户端镜像，以 agent/session 共用 id 为键）在会话行进入列表镜像时出生，随 prune 死亡。契约：api-contracts v3 §4。`ConversationSnapshot` 携带两项由 Host 拥有的完整日志投影。`todos` 来自 history 尾页，在向前加载较早页面时保留，并随实时 `todo/write` 事件更新。持久 `metrics` 来自 history 尾页和实时 `session/metrics` 帧，在向前加载较早页面时保留，并且只接受日志修订号与投影修订号均不减小的数据。Session 另行保留当前 mux 连接观察到的最新 `session/model-request` 容量，并在普通用量／压力更新期间把它覆盖到 metrics 上。后续请求会替换或清除该值，`session/subscribed` 则同时清除指标顺序状态与容量；因此，重连、恢复和新订阅都不会显示百分比，直到观察到另一次请求。缺失的 metrics 保持为 `null`，而不是根据可见节点窗口推断。
+客户端 cordis 启动与不依赖 React 的对象服务：SlotsService 包装 SlotCore 并提供 renderer 数据源；SessionsService 拥有 Session 对象、列表／scope／history 状态；WorkspacesService 依赖 SessionsService，拥有 Workspace 对象、列表／操作、默认目标派生，以及 New Session 空会话复用入口（`connectWorkspace`）。运行时把共享 Host 流分发给两个 manager。客户端 Session 一律由 Host 出生（一次 `session.create` 同瞬产出 Session+Agent+cwd）；客户端不持有任何实体化之前的会话状态——Agent scope（host dsh-scope 的客户端镜像，以 agent/session 共用 id 为键）在会话行进入列表镜像时出生，随 prune 死亡。契约：api-contracts v3 §4。`todos` 与 `title` 等通用完整日志领域值存放在逐会话投影值仓中：history 尾页的 `projections` 为其播种，`session/projection` 帧按较高 seq 优先更新，消费方通过 `useProjection` 按 key 读取。持久的 `ConversationSnapshot.metrics` 则来自独立的 history 尾页值与实时 `session/metrics` 帧，因为即时 token-meter 压力可以在相同持久日志修订号上继续变化；客户端只接受日志修订号与投影修订号均不减小的数据。`ConversationSnapshot.modelRequestContextWindow` 另行保留当前 mux 连接观察到的最新 `session/model-request` 容量。后续请求会替换或清除该值，`session/subscribed` 则同时清除指标顺序状态与容量；因此，重连、恢复和新订阅都不会显示百分比，直到观察到另一次请求。缺失的 metrics 保持为 `null`，而不是根据可见节点窗口推断。

 ## Workspace 与 Session 列表

@@ -22,7 +22,7 @@ SlotsService 分别为 renderer 提供 `useSessions` 与 `useWorkspaces` 的裸

 ## Session 标题投影

-`SessionManager` 独立于列表和 Session 实例到达情况，保留最近一次通过验证的 `session/title` 控制快照。seq 更新的事件会替换旧快照，标题时间戳计入列表新近程度；订阅基线会先丢弃 seq 超过其 `lastSeq` 的任何已保留标题，再接收可选的折叠标题。显式移除 Session 也会清除已保留标题。因此，面向客户端的 `SessionSummary.title` 只包含真实的持久标题；`displayTitle` 始终存在，并依次回退到 cwd basename 和 Session id。冷启动的持久会话会保持该回退值，直到打开或恢复会话，促使主机折叠并投影日志支持的标题。
+`SessionManager` 独立于 Session 实例是否到达而保留逐会话通用投影值仓，因此实时 `title` 帧可以在会话打开前更新列表行。订阅基线会截断 seq 超过 `lastSeq` 的投影行；下一份 history 尾页基线重新播种持久值，显式移除 Session 则清除该值仓。因此，面向客户端的 `SessionSummary.title` 只包含真实的持久标题；`title` key 缺失时，`displayTitle` 始终依次回退到 cwd basename 和 Session id。

 ## 会话模型选择

--- a/packages/client/runtime/package.json
+++ b/packages/client/runtime/package.json
@@ -32,10 +32,13 @@
  "license": "BSD-3-Clause",
  "dependencies": {
    "@deepseek-ai/dsh-client-connection": "workspace:^",
+    "@deepseek-ai/dsh-commands": "workspace:^",
    "@deepseek-ai/dsh-client-ui-slots": "workspace:^",
    "@deepseek-ai/dsh-host-apiproxy": "workspace:^",
    "@deepseek-ai/dsh-llm": "workspace:^",
    "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-session-projection": "workspace:^",
+    "@deepseek-ai/dsh-session-title": "workspace:^",
    "immer": "^10.1.1",
    "react": "^18.2.0",
    "zustand": "~4.4.7"
--- a/packages/client/runtime/src/client/index.ts
+++ b/packages/client/runtime/src/client/index.ts
@@ -7,6 +7,7 @@ import { SessionsService } from './sessions/service.ts'
 import type { SessionListState } from './sessions/service.ts'
 import { WorkspacesService } from './workspaces/service.ts'
 import type { ConversationSnapshot, RunningToolCall, ToolResultNode } from './sessions/conversation.ts'
+import type { UseProjection } from './sessions/projection-store.ts'

 export { SlotsService } from './slots.ts'
 export type { RootOwnerProps } from './slots.ts'
@@ -28,12 +29,17 @@ export type {
  EngineStoreHandle, EngineStoreInstance, ObservableSnapshot, SnapshotStore,
 } from './contract/store.ts'
 export type {
-  AssistantBlock, AssistantMessageNode, CodeSubCall, ComposerPhase, ContextMessageNode, ConversationNode,
+  AssistantBlock, AssistantMessageNode, CodeSubCall, CommandNode, ComposerPhase, ContextMessageNode, ConversationNode,
  ConversationSnapshot, QueuedMessage, RunningToolCall,
-  SteeringMessageNode, TodoItem, ToolResultNode, UnknownSurfaceNode, UserMessageNode,
+  SteeringMessageNode, ToolResultNode, UnknownSurfaceNode, UserMessageNode,
 } from './sessions/conversation.ts'
 export { PendingWait } from './sessions/pending.ts'
 export type { PendingInteraction, PendingKind, PendingPayloads } from './sessions/pending.ts'
+// Projection value store (session-projection RFC, push model): host-computed
+// whole values per key; domains ship projection support with zero client code.
+export type {
+  ProjectionsBaseline, ProjectionValueStore, SessionProjectionMap, UseProjection,
+} from './sessions/projection-store.ts'
 export type { SessionId } from '@deepseek-ai/dsh-client-connection/client'

 /** Client-side Cordis context after declaration merging. */
@@ -59,12 +65,16 @@ declare module '@deepseek-ai/dsh-client-ui-slots' {
    useSession: SnapshotSelectorHook<ConversationSnapshot>
    /** The framework-resolved session id (owners never pass it). */
    sessionId: SessionId
+    /** The fifth framework hook seat: key-addressed projection reader (undefined = capability absent). */
+    useProjection: UseProjection
  }
  /** Standard kit for slots that remain mounted while current session changes. */
  interface SessionMaybeStandardProps {
    useSession: MaybeSnapshotSelectorHook<ConversationSnapshot>
    /** Current session id; absent in the no-session state. */
    sessionId: SessionId | undefined
+    /** Key-addressed projection reader; every key reads absent while no session is current. */
+    useProjection: UseProjection
  }
  /** Props injected into every global slot component. */
  interface GlobalStandardProps {
--- a/packages/client/runtime/src/client/sessions/conversation.ts
+++ b/packages/client/runtime/src/client/sessions/conversation.ts
@@ -3,24 +3,13 @@
 // substructures keep their references (the React.memo premise). callId/approvalId stay plain
 // string here (narrow to real brands when convenient).

+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
-import type { TodoItem } from '@deepseek-ai/dsh-session/types'
 import type {
  RpcError, SessionId, SessionMetrics, ToolCallView, ToolResultView,
 } from '@deepseek-ai/dsh-client-connection/client'
 import type { PendingInteraction } from './pending.ts'

-export type { TodoItem }
-
-/**
- * Durable Host metrics with the latest capacity observed on this live mux
- * connection overlaid for presentation.
- */
-export interface ConversationMetrics extends SessionMetrics {
-  /** Latest observed request-attempt capacity; absent until observed or after reset/clear. */
-  contextWindow?: number
-}
-
 /** Assistant content blocks sorted by what the UI cares about
 *  (text body / collapsible reasoning / tool-call card head / other fallback). */
 export type AssistantBlock =
@@ -129,6 +118,31 @@ export interface UnknownSurfaceNode {
  data: unknown
 }

+/**
+ * One slash-command lifecycle folded from the log-only `command/run` /
+ * `command/done` pair (paired by commandId, mirroring tool call↔result).
+ * Log-only events never enter the surface fold, so the FoldAdapter indexes
+ * them separately and merges the nodes into the flow by seq. A window cut
+ * between the pair soft-falls like tool pairs: a done with no in-window run
+ * still builds a node (name/args null), and a run with no done renders as
+ * still executing.
+ */
+export interface CommandNode {
+  kind: 'command'
+  /** Seq of the command/run event; the done event's seq when only the done is in-window. */
+  seq: number
+  /** Unix epoch ms of the anchoring event. */
+  time: number
+  /** Pairing id minted by the host executor. */
+  commandId: CommandId
+  /** Command name (run payload's structured field); null when the run fell outside the window. */
+  name: string | null
+  /** Verbatim rawInput after the name, separator whitespace included (run payload); null when the run fell outside the window. */
+  args: string | null
+  /** Settlement outcome (done payload); null while the command is still executing. */
+  outcome: { kind: 'success' | 'error'; text?: string } | null
+}
+
 /** Finalized conversation node union (kind discriminates; seq is the React key). */
 export type ConversationNode =
  | UserMessageNode
@@ -136,6 +150,7 @@ export type ConversationNode =
  | SteeringMessageNode
  | ContextMessageNode
  | ToolResultNode
+  | CommandNode
  | UnknownSurfaceNode

 /**
@@ -252,13 +267,16 @@ export interface ConversationSnapshot {
   */
  blank: boolean
  lastAgentError: string | null
-  /** Current whole-list `todo/write` projection — the tail page's full-log value, then each live
-   *  write (last write wins); empty = the log holds no plan. */
-  todos: readonly TodoItem[]
  /**
-   * Host-owned cumulative usage/current pressure with live mux-local capacity
-   * overlaid. Independent of `nodes` pagination; null until a tail response or
-   * live metrics frame supplies a current durable value.
+   * Host-owned cumulative usage/current pressure. Independent of `nodes`
+   * pagination; null until a tail response or live metrics frame supplies a
+   * current durable value.
   */
-  metrics: ConversationMetrics | null
+  metrics: SessionMetrics | null
+  /**
+   * Capacity from the latest model-request attempt observed on this mux
+   * generation. Absent before the first such request, after a request whose
+   * registration exposes no capacity, and after `session/subscribed`.
+   */
+  modelRequestContextWindow?: number
 }
--- a/packages/client/runtime/src/client/sessions/fold-adapter.ts
+++ b/packages/client/runtime/src/client/sessions/fold-adapter.ts
@@ -8,8 +8,9 @@ import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
 // go through it — the package root points at lib/index.js (needs a build) which the vite
 // browser bundle cannot resolve; surface.ts has no Node dependencies.
 import { SurfaceManager, isSurfaceEligibleType } from '@deepseek-ai/dsh-session/surface'
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type { ToolCallView, ToolEventView, ToolResultView } from '@deepseek-ai/dsh-client-connection/client'
-import type { ConversationNode } from './conversation.ts'
+import type { CommandNode, ConversationNode } from './conversation.ts'
 import { toAssistantBlocks } from './conversation.ts'

 /** In-window tool/call index entry (result-card backfill + runningCalls material). */
@@ -99,6 +100,15 @@ export class FoldAdapter {
  private callIdx = new Map<string, CallIndexEntry>()
  /** Wire result views keyed by the tool/result event's seq (views ride the envelope, not the event). */
  private resultViews = new Map<number, ToolResultView>()
+  /**
+   * Command lifecycle nodes by commandId (insertion = run order). The
+   * `command/run`/`command/done` pair is log-only, so the surface fold never
+   * emits it; this index folds the pair (done settles its run's node in
+   * place) and nodes() merges the products into the flow by seq. Window cuts
+   * soft-fall like tool pairs: a done with no in-window run still builds a
+   * node.
+   */
+  private commandIdx = new Map<string, CommandNode>()
  /** Window revision (bumped on reset/append) keying the nodes() result cache: an unchanged
   *  window returns the previous ARRAY reference, not just cached elements — the snapshot's
   *  reference-stability contract (§A.9.4) starts here. */
@@ -128,10 +138,14 @@ export class FoldAdapter {
    this.degraded = false
    this.callIdx = new Map()
    this.resultViews.clear()
+    this.commandIdx = new Map()
    for (let i = 0; i < events.length; i++) {
      const event = events[i]
      /* v8 ignore next -- dense-array guard: i stays within events.length, so the undefined arm needs a sparse array no caller builds. */
-      if (event !== undefined) this.indexCall(event, views?.[i])
+      if (event !== undefined) {
+        this.indexCall(event, views?.[i])
+        this.indexCommand(event)
+      }
    }
  }

@@ -145,6 +159,7 @@ export class FoldAdapter {
    this.rev++
    this.padded.push(event)
    this.indexCall(event, view)
+    this.indexCommand(event)
  }

  /**
@@ -180,7 +195,23 @@ export class FoldAdapter {
      this.nodeCache.set(seq, node)
      out.push(node)
    }
-    const value = { nodes: out, degraded: this.degraded }
+    // Command nodes fold outside the surface (log-only events); merge by seq.
+    // Both inputs are seq-ascending (surface order and run-index insertion
+    // order share the log order), so one linear merge keeps flow order.
+    let nodes = out
+    if (this.commandIdx.size > 0) {
+      nodes = []
+      const commands = [...this.commandIdx.values()]
+      let next = 0
+      for (const node of out) {
+        for (let cmd = commands[next]; cmd !== undefined && cmd.seq < node.seq; cmd = commands[++next]) {
+          nodes.push(cmd)
+        }
+        nodes.push(node)
+      }
+      for (let cmd = commands[next]; cmd !== undefined; cmd = commands[++next]) nodes.push(cmd)
+    }
+    const value = { nodes, degraded: this.degraded }
    this.nodesResult = { rev: this.rev, value }
    return value
  }
@@ -195,6 +226,36 @@ export class FoldAdapter {
    return seqs
  }

+  /** Fold one command lifecycle event into its node (run mints, done settles in place; done-only soft-falls). */
+  private indexCommand(event: SessionEvent): void {
+    // Log-only plugin events: the host-side dsh-commands declaration cannot
+    // enter the client program, so this wire consumer narrows structurally
+    // (the same posture as tool/code-dispatch in session.ts).
+    if ((event.type as string) === 'command/run') {
+      const data = event.data as unknown as { commandId: CommandId; name: string; args: string }
+      this.commandIdx.set(data.commandId, {
+        kind: 'command', seq: event.seq, time: event.time,
+        commandId: data.commandId, name: data.name, args: data.args, outcome: null,
+      })
+      return
+    }
+    if ((event.type as string) !== 'command/done') return
+    const data = event.data as unknown as { commandId: CommandId; kind: 'success' | 'error'; text?: string }
+    const run = this.commandIdx.get(data.commandId)
+    const outcome = { kind: data.kind, ...data.text === undefined ? {} : { text: data.text } }
+    if (run === undefined) {
+      // Cross-window cut: the run page fell out of the window — build the
+      // node from the done alone (same soft-fall as a call-less tool result).
+      this.commandIdx.set(data.commandId, {
+        kind: 'command', seq: event.seq, time: event.time,
+        commandId: data.commandId, name: null, args: null, outcome,
+      })
+      return
+    }
+    // Settle in place: a fresh node object (published references stay immutable).
+    this.commandIdx.set(data.commandId, { ...run, outcome })
+  }
+
  private indexCall(event: SessionEvent, view?: ToolEventView): void {
    if (event.type === 'tool/result') {
      if (view?.for === 'result') this.resultViews.set(event.seq, view.view)
--- a/packages/client/runtime/src/client/sessions/manager.ts
+++ b/packages/client/runtime/src/client/sessions/manager.ts
@@ -9,7 +9,12 @@ import { transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
 import { mergeOrderedBaseline } from '../ordered-baseline.ts'
 import type { SessionListEntry, TitledSessionSummary } from './lineage.ts'
 import { flattenLineage } from './lineage.ts'
+// Type-only merge edge: the title domain's client-namespace outlet declares
+// the 'title' projection key this manager projects into list rows (and any
+// useProjection('title') consumer reads). Zero value imports by construction.
+import type {} from '@deepseek-ai/dsh-session-title/client'
 import { Notifier } from './notifier.ts'
+import { ProjectionValueStore } from './projection-store.ts'
 import { Session } from './session.ts'

 /**
@@ -43,12 +48,6 @@ type SessionListMutation =
 /** Per-session cap for pre-instantiation approval/question buffering (low-frequency frames; a few dozen covers any real backlog). */
 const PENDING_BUFFER_CAP = 32

-/** Latest title control snapshot retained independently of list/instance arrival. */
-interface SessionTitleSnapshot {
-  title: string
-  eventSeq: number
-  updatedAt: number
-}

 /** Instance cluster + frame entry + the session list (see the web client architecture RFC). */
 export class SessionManager {
@@ -58,7 +57,11 @@ export class SessionManager {
   *  drop-and-backfill path; replayed and cleared on instantiation. Bounded per session (these
   *  frames are low-frequency; overflow drops oldest) and dropped on session-removed (audit S7). */
  private readonly pendingBuffers = new Map<SessionId, RpcRequest<MuxFrame>[]>()
-  private readonly titleSnapshots = new Map<SessionId, SessionTitleSnapshot>()
+  /** Per-session projection value stores, retained independently of instance arrival (the
+   *  title-snapshot precedent, generalized): push frames land here whether or not the Session
+   *  is instantiated (list rows read the 'title' key), and an instantiated Session adopts the
+   *  same store so history-baseline seeding and frames converge on one row set. */
+  private readonly projectionStores = new Map<SessionId, ProjectionValueStore>()
  private summaries: SessionSummary[] = []
  private listState: 'idle' | 'loading' | 'error' = 'idle'
  /** Arrival phase; the pending → ready edge fires on the first successful pull (see SessionListPhase). */
@@ -163,9 +166,23 @@ export class SessionManager {
      onEngaged: (engaged) => {
        this.recordMutation({ kind: 'engaged', sessionId: engaged.sessionId })
      },
+      projections: this.projectionStore(sessionId),
    })
  }

+  /** Resident per-session projection store (create-on-demand; outlives instantiation). */
+  private projectionStore(sessionId: SessionId): ProjectionValueStore {
+    let store = this.projectionStores.get(sessionId)
+    if (store === undefined) {
+      store = new ProjectionValueStore()
+      // List rows project off store keys (title); any-key changes re-enter
+      // the manager's own batched rebuild channel.
+      store.subscribeAny(() => { this.notifier.markDirty() })
+      this.projectionStores.set(sessionId, store)
+    }
+    return store
+  }
+
  // ---- List surface ----

  /** Full refresh via session.list (single-flight: an in-flight call is reused). */
@@ -302,23 +319,20 @@ export class SessionManager {
  handleMuxEnvelope(envelope: RpcRequest<MuxFrame>): void {
    const frame = envelope.payload
    if (frame.type === 'stream/error') return // Controller already treats this as stream failure
-    if (frame.type === 'session/title') {
-      const current = this.titleSnapshots.get(frame.sessionId)
-      if (current !== undefined && current.eventSeq >= frame.eventSeq) return
-      this.titleSnapshots.set(frame.sessionId, {
-        title: frame.title,
-        eventSeq: frame.eventSeq,
-        updatedAt: frame.updatedAt,
-      })
+    if (frame.type === 'session/projection') {
+      // Finished host-computed value: land it in the resident store whether or
+      // not the Session is instantiated (list rows read the 'title' key). The
+      // synchronous markDirty keeps the list snapshot same-tick fresh (the
+      // store's own any-key channel is microtask-batched).
+      this.projectionStore(frame.sessionId).apply(frame.key, frame.value, frame.seq)
      this.notifier.markDirty()
      return
    }
    if (frame.type === 'session/subscribed') {
-      const current = this.titleSnapshots.get(frame.sessionId)
-      if (current !== undefined && current.eventSeq > frame.lastSeq) {
-        this.titleSnapshots.delete(frame.sessionId)
-        this.notifier.markDirty()
-      }
+      // Rows past the host's durable baseline rode state a restart lost; drop
+      // them so last-wins cannot pin a phantom value over recomputed truth.
+      this.projectionStores.get(frame.sessionId)?.truncate(frame.lastSeq)
+      this.notifier.markDirty()
      // New mux-generation baseline: buffered session/queued frames belong to
      // the previous generation and the host is about to resend the live
      // snapshot — drop them, or every reconnect appends a duplicate batch
@@ -377,7 +391,7 @@ export class SessionManager {
        this.recordMutation({ kind: 'remove', sessionId: frame.sessionId })
        this.sessions.get(frame.sessionId)?.handleRemoved() // instance survives (resident-instance rule), only flagged in the snapshot
        this.pendingBuffers.delete(frame.sessionId) // a removed session's buffered frames must not replay on a future instantiation
-        this.titleSnapshots.delete(frame.sessionId)
+        this.projectionStores.delete(frame.sessionId) // removed sessions drop their projection rows with the instance
        return
      }
      case 'host/session-status': {
@@ -402,10 +416,12 @@ export class SessionManager {

  private buildListSnapshot(): SessionListSnapshot {
    const merged: TitledSessionSummary[] = this.summaries.map((summary) => {
-      const title = this.titleSnapshots.get(summary.sessionId)
-      return title === undefined
-        ? summary
-        : { ...summary, title: title.title, updatedAt: Math.max(summary.updatedAt, title.updatedAt) }
+      // List rows read the generic 'title' projection key (host-computed unit
+      // value; the bespoke session/title frame is retired).
+      const title = this.projectionStores.get(summary.sessionId)?.get('title')
+      return typeof title === 'string' && title !== ''
+        ? { ...summary, title }
+        : summary
    })
    const fresh = flattenLineage(merged)
    const items = fresh.map((entry) => {
--- a/packages/client/runtime/src/client/sessions/projection-store.ts
+++ b/packages/client/runtime/src/client/sessions/projection-store.ts
@@ -0,0 +1,183 @@
+/**
+ * Generic per-session projection value store (session-projection RFC, push
+ * model): the host is the only computation site; the client holds finished
+ * whole values per key — `key → { value, seq }` — seeded by the history tail
+ * page's projections block and updated by `session/projection` push frames,
+ * under the single rule **higher seq wins**. No client-side domain folding
+ * exists: a domain ships projection support with zero client code. Per-key
+ * bare observable faces feed `useProjection` (web-react binds them).
+ */
+import type { SessionProjectionMap } from '@deepseek-ai/dsh-session-projection/types'
+import type { ObservableSnapshot } from '../contract/store.ts'
+import { Notifier } from './notifier.ts'
+
+// The single projection type table, typed end to end (host unit, wire block,
+// client store, React hook) — the interface package's pure-type outlet
+// (`/types`, zero imports), never the package root: the root's dsh-agent →
+// dsh-session chain would drag the host `Context.sessions` merge into the
+// client program (one program must not hold both sides). No second
+// client-side "views" table (user ruling, RFC Alternatives).
+export type { SessionProjectionMap } from '@deepseek-ai/dsh-session-projection/types'
+
+/**
+ * The fifth framework hook seat (session-projection RFC): key-addressed
+ * projection reader delivered through the standard kit. `undefined` uniformly
+ * means capability absent — host unit unmounted, or no baseline/frame has
+ * carried the key yet. The selector overload mirrors useSession (per-key uSES
+ * binding; reference stability holds because a key's value reference changes
+ * only when a frame or baseline lands).
+ */
+export type UseProjection = {
+  <K extends Extract<keyof SessionProjectionMap, string>>(key: K): SessionProjectionMap[K] | undefined
+  <K extends Extract<keyof SessionProjectionMap, string>, S>(
+    key: K,
+    selector: (value: SessionProjectionMap[K] | undefined) => S,
+    eq?: (a: S, b: S) => boolean,
+  ): S
+}
+
+/**
+ * Tail-page projections baseline — structurally identical to the wire's
+ * `SessionProjectionsBlock` (apiproxy api layer), restated here so the
+ * React-free store depends only on the type table, not the wire package's
+ * response vocabulary.
+ */
+export interface ProjectionsBaseline {
+  /** The consistent-cut seq (equals the window tail seq by construction). */
+  asOfSeq: number
+  /** Whole current values by key; a registered key absent here means the capability is absent. */
+  values: Partial<SessionProjectionMap>
+}
+
+/** One key's row: the latest finished value and the seq it is consistent with. */
+interface Row {
+  value: unknown
+  seq: number
+}
+
+/** Per-key notification channel: the bare face plus its batching notifier. */
+interface Channel {
+  face: ObservableSnapshot<unknown>
+  notifier: Notifier
+}
+
+/**
+ * One session's projection values. Framework semantics, uniform across every
+ * key: a baseline seeds rows at its cut, a push frame updates one row, and in
+ * both paths a lower-or-equal seq loses — a replayed frame cannot regress a
+ * value, a stale baseline cannot overwrite a newer frame. A key the store has
+ * never seen reads `undefined` (capability absent). Faces are identity-stable
+ * per key (create-on-demand, cached) so the React side binds each exactly
+ * once; the store-level channel (`subscribeAny`) serves coarse consumers (the
+ * manager's list projection reads the `title` key).
+ */
+export class ProjectionValueStore {
+  private readonly rows = new Map<string, Row>()
+  private readonly channels = new Map<string, Channel>()
+  /** Coarse any-key channel (no snapshot cache to rebuild: reads hit rows directly). */
+  private readonly anyNotifier = new Notifier(() => {})
+
+  /**
+   * Key-addressed bare observable face (the useProjection resolution path).
+   * Always defined — absence is an `undefined` snapshot, never a missing
+   * face, so a component may subscribe before the key ever carries a value.
+   * @param key - projection key.
+   * @returns the identity-stable face for this key.
+   */
+  faceOf(key: string): ObservableSnapshot<unknown> {
+    return this.channel(key).face
+  }
+
+  /**
+   * Current whole value for a key (erased framework read; typed reads go
+   * through `useProjection`'s map lookup).
+   * @param key - projection key.
+   * @returns the value, or undefined while the key is absent.
+   */
+  get(key: string): unknown {
+    return this.rows.get(key)?.value
+  }
+
+  /**
+   * Subscribe to any-key changes (microtask-batched) — the manager's list
+   * rebuild channel.
+   * @param listener - change callback.
+   * @returns the unsubscribe function.
+   */
+  subscribeAny(listener: () => void): () => void {
+    return this.anyNotifier.subscribe(listener)
+  }
+
+  /**
+   * Apply one finished value (the `session/projection` push-frame path).
+   * @param key - projection key.
+   * @param value - whole value computed by the host unit.
+   * @param seq - the unit's watermark at emission.
+   */
+  apply(key: string, value: unknown, seq: number): void {
+    const row = this.rows.get(key)
+    if (row !== undefined && seq <= row.seq) return // higher seq wins; replays and stale frames drop
+    this.rows.set(key, { value, seq })
+    this.changed(key)
+  }
+
+  /**
+   * Seed from a history tail page's projections block: every carried key
+   * lands under the same seq rule as frames; a key the block omits is
+   * capability-absent as of the cut — its row clears unless a newer frame
+   * already superseded the cut (a stale baseline can neither overwrite nor
+   * clear newer values).
+   * @param baseline - the response's projections block.
+   */
+  seed(baseline: ProjectionsBaseline): void {
+    // Erased walk: the framework crosses the open key space; per-key typing
+    // is re-established at the consumer (useProjection's map lookup).
+    const values = baseline.values as Record<string, unknown>
+    for (const key of Object.keys(values)) this.apply(key, values[key], baseline.asOfSeq)
+    for (const [key, row] of this.rows) {
+      if (Object.hasOwn(values, key)) continue
+      if (row.seq > baseline.asOfSeq) continue
+      this.rows.delete(key)
+      this.changed(key)
+    }
+  }
+
+  /**
+   * Drop rows past a mux-generation baseline (`session/subscribed.lastSeq`):
+   * a row claiming knowledge beyond the host's own durable baseline rode
+   * state a restart lost — under last-wins it would wrongly outrank the
+   * host's recomputed (lower-seq) values forever. Durable replay and the next
+   * baseline re-seed whatever truly survived (the title-snapshot precedent,
+   * generalized).
+   * @param lastSeq - the subscribed frame's durable baseline seq.
+   */
+  truncate(lastSeq: number): void {
+    for (const [key, row] of this.rows) {
+      if (row.seq <= lastSeq) continue
+      this.rows.delete(key)
+      this.changed(key)
+    }
+  }
+
+  private changed(key: string): void {
+    this.channels.get(key)?.notifier.markDirty()
+    this.anyNotifier.markDirty()
+  }
+
+  private channel(key: string): Channel {
+    let channel = this.channels.get(key)
+    if (channel === undefined) {
+      // The notifier only batches (no snapshot cache to rebuild: faces read rows directly).
+      const notifier = new Notifier(() => {})
+      channel = {
+        notifier,
+        face: {
+          getSnapshot: () => this.rows.get(key)?.value,
+          subscribe: listener => notifier.subscribe(listener),
+        },
+      }
+      this.channels.set(key, channel)
+    }
+    return channel
+  }
+}
--- a/packages/client/runtime/src/client/sessions/service.ts
+++ b/packages/client/runtime/src/client/sessions/service.ts
@@ -301,7 +301,7 @@ export class SessionsService {
        props[name] = undefined
      }
    }
-    return { sessionId: undefined, hooks, props }
+    return { sessionId: undefined, hooks, props } // no projections face: every key reads absent without a session
  }

  /** Materialize the standard-props bundle for one session (fails loud on duplicate member names). */
@@ -334,7 +334,14 @@ export class SessionsService {
        props[name] = contributedProps[name]
      }
    }
-    return { sessionId: binding.sessionId, hooks, props }
+    return {
+      sessionId: binding.sessionId,
+      hooks,
+      props,
+      // The useProjection seat: key-addressed bare value faces off the
+      // session's projection store (open key space — never a static roster member).
+      projections: { faceOf: key => binding.session.projections.faceOf(key) },
+    }
  }

  /**
--- a/packages/client/runtime/src/client/sessions/session.ts
+++ b/packages/client/runtime/src/client/sessions/session.ts
@@ -2,7 +2,7 @@

 import type { Context } from 'cordis'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
-import type { SessionEvent, TodoItem } from '@deepseek-ai/dsh-session/types'
+import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
 import type {
  HistoryEntry, IApiClient, MuxFrame, RpcError, RpcId, RpcResult,
  SessionId, SessionMetrics, ToolEventView,
@@ -12,7 +12,7 @@ import type {
 import { transportError } from '@deepseek-ai/dsh-host-apiproxy/api'
 import type { ObservableSnapshot } from '../contract/store.ts'
 import type {
-  CodeSubCall, ComposerPhase, ConversationMetrics, ConversationNode, ConversationSnapshot, OpenState,
+  CodeSubCall, ComposerPhase, ConversationNode, ConversationSnapshot, OpenState,
  PromptError, QueuedMessage, RunningToolCall,
 } from './conversation.ts'
 import type { PendingInteraction } from './pending.ts'
@@ -20,6 +20,8 @@ import { PendingWait } from './pending.ts'
 import { FoldAdapter } from './fold-adapter.ts'
 import { Notifier } from './notifier.ts'
 import { PartialAccumulator } from './partial.ts'
+import { ProjectionValueStore } from './projection-store.ts'
+import type { ProjectionsBaseline } from './projection-store.ts'

 /** Messages requested per history page. */
 export const PAGE_MESSAGES = 50
@@ -35,6 +37,12 @@ export interface SessionOptions {
   * (hidden, still reusable by connectWorkspace).
   */
  onEngaged?(session: Session): void
+  /**
+   * Manager-owned projection value store to adopt (frames route through the
+   * manager and values outlive instantiation); omitted, the Session owns a
+   * private store (bare object-layer construction).
+   */
+  projections?: ProjectionValueStore
 }

 /** Queue-row preview cap: the dock renders one line, the full content never leaves the host mirror. */
@@ -99,11 +107,8 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
  private queueCache: { rev: number; value: QueuedMessage[] } | null = null
  private frozenRev = 0
  private nodesCache: { folded: readonly ConversationNode[]; frozenRev: number; value: readonly ConversationNode[] } | null = null
-  /** Current whole-list todo/write projection: each tail history response replaces it (an omitted
-   *  field is the authoritative empty list) and every live write overwrites it. */
-  private todos: readonly TodoItem[] = []
-  /** Host-owned metrics with current-connection request capacity overlaid. */
-  private metrics: ConversationMetrics | null = null
+  /** Host-owned durable usage/current-pressure projection. */
+  private metrics: SessionMetrics | null = null
  /** Latest capacity observed on this mux connection, independent of durable metrics arrival. */
  private contextWindow: number | undefined
  /** `run_code` sub-dispatches by parent callId (window-derived, like openCalls). Appends
@@ -130,6 +135,19 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
  /** subscribed.lastSeq baseline (gap detection; null when no subscribed frame arrived — degrade to the liveBuffer dedup path). */
  private subscribedLastSeq: number | null = null

+  /**
+   * Per-session projection value store (session-projection RFC, push model):
+   * finished whole values computed on the host, seeded by the tail page's
+   * projections block and updated by `session/projection` frames under the
+   * one higher-seq-wins rule. Keys are read via `projections.faceOf(key)`
+   * (the useProjection resolution face); the conversation snapshot never
+   * carries projection values, and no client-side domain folding exists.
+   * Manager-owned when constructed through SessionManager (frames route and
+   * the store outlives instantiation, the title-snapshot precedent); a bare
+   * construction gets a private store.
+   */
+  readonly projections: ProjectionValueStore
+
  private snapshotCache: ConversationSnapshot
  private readonly notifier = new Notifier(() => {
    this.snapshotCache = this.buildSnapshot()
@@ -153,6 +171,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
    private readonly api: IApiClient,
    private readonly options: SessionOptions = {},
  ) {
+    this.projections = options.projections ?? new ProjectionValueStore()
    this.snapshotCache = this.buildSnapshot()
  }

@@ -360,6 +379,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
      }
      case 'session/subscribed': {
        this.subscribedLastSeq = frame.lastSeq
+        let changed = false
        // New mux-generation baseline: the host pushes this session's queue
        // snapshot AFTER the subscribed frame on the same stream, so the
        // stale mirror clears here — race-free against onConnected/resync
@@ -367,13 +387,17 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
        if (this.queued.length > 0) {
          this.queued = []
          this.queueRev++
-          this.notifier.markDirty()
+          changed = true
+        }
+        if (this.contextWindow !== undefined) {
+          this.contextWindow = undefined
+          changed = true
        }
-        this.contextWindow = undefined
        if (this.metrics !== null) {
          this.metrics = null
-          this.notifier.markDirty()
+          changed = true
        }
+        if (changed) this.notifier.markDirty()
        return
      }
      case 'session/metrics': {
@@ -383,13 +407,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
      case 'session/model-request': {
        if (this.contextWindow === frame.contextWindow) return
        this.contextWindow = frame.contextWindow
-        if (this.metrics !== null) {
-          const { contextWindow: _previous, ...durable } = this.metrics
-          this.metrics = frame.contextWindow === undefined
-            ? durable
-            : { ...durable, contextWindow: frame.contextWindow }
-          this.notifier.markDirty()
-        }
+        this.notifier.markDirty()
        return
      }
      case 'approval/requested': {
@@ -508,7 +526,12 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
        this.openError = result.error
        return
      }
-      this.installWindow(result.value.events, result.value.hasMore, result.value.todos, result.value.metrics)
+      this.installWindow(
+        result.value.events,
+        result.value.hasMore,
+        result.value.projections,
+        result.value.metrics,
+      )
      // Gap detection (§D.3-4): baseline past the window tail and liveBuffer did not cover it -> pull the tail page once more.
      const tailSeq = this.windowTailSeq()
      if (this.subscribedLastSeq !== null && tailSeq !== null && this.subscribedLastSeq > tailSeq) {
@@ -518,7 +541,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
          this.installWindow(
            result.value.events,
            result.value.hasMore,
-            result.value.todos,
+            result.value.projections,
            result.value.metrics,
          )
        }
@@ -538,28 +561,24 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
  /** Install the history window + stitch the liveBuffer (seq is the sole dedup key).
   *  Stitching MUST NOT route through acceptLiveEvent: openState is still 'loading' here
   *  (doOpen flips it after install), so recursing would push every buffered event straight
-   *  back into liveBuffer where nothing ever drains it — a silent drop loop (audit S1). */
+   *  back into liveBuffer where nothing ever drains it — a silent drop loop (audit S1).
+   *  A carried projections block seeds the value store (higher seq wins, so a stale
+   *  baseline cannot overwrite a newer push frame); the window events themselves are
+   *  never folded — the host is the only computation site. */
  private installWindow(
    entries: HistoryEntry[],
    hasMore: boolean,
-    todos: readonly TodoItem[] | undefined,
+    projections: ProjectionsBaseline | undefined,
    metrics: SessionMetrics | undefined,
  ): void {
    this.events = entries.map(e => e.event)
    this.views = entries.map(e => e.view)
    this.baseSeq = this.events[0]?.seq ?? 0
    this.hasMore = hasMore
-    // Session-level projection from the tail page (full-log latest todo/write,
-    // independent of the window); an in-window write below re-derives the same
-    // value, and later live events keep overwriting it. Every caller here is a
-    // tail request (no beforeSeq), which the host answers with the projection
-    // or omits it only when the full log holds no todo/write — so an absent
-    // field is the authoritative empty list, not a missing carrier. Assigning
-    // it clears a plan the log never kept (a write lost to a host crash).
-    this.todos = todos ?? []
-    if (metrics !== undefined) this.installMetrics(metrics)
    this.foldAdapter.reset(this.events, this.baseSeq, this.views)
    this.rebuildDerivedFromWindow()
+    if (projections !== undefined) this.projections.seed(projections)
+    if (metrics !== undefined) this.installMetrics(metrics)
    const buffered = this.liveBuffer
    this.liveBuffer = []
    for (const item of buffered) this.appendLive(item.event, item.view)
@@ -611,7 +630,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
        this.installWindow(
          result.value.events,
          result.value.hasMore,
-          result.value.todos,
+          result.value.projections,
          result.value.metrics,
        )
      }
@@ -733,10 +752,6 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
        if (this.openCalls.delete(String(event.data.callId))) this.callsRev++
        return
      }
-      case 'todo/write': {
-        this.todos = event.data.todos
-        return
-      }
      case 'turn/end': {
        // Aborted turns never finalize. The accumulated partial is VALUE, not residue: freeze it
        // into an interrupted terminal node (pulse stops, text survives) instead of deleting it.
@@ -781,10 +796,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {

  /** Re-derive state (partial/openCalls/frozenNodes) from raw window events after a rebuild — keeps
   *  paging/stitching consistent, and makes the live freeze and the history replay converge on the
-   *  same interrupted nodes (chunks are logged, so the replayed sweep re-freezes identical text).
-   *  todos is deliberately NOT reset: it is session-level (seeded by the tail page's full-log
-   *  projection, not derivable from an arbitrary window). The window always extends to the log
-   *  tail, so an in-window todo/write can only overwrite it with the same latest value. */
+   *  same interrupted nodes (chunks are logged, so the replayed sweep re-freezes identical text). */
  private rebuildDerivedFromWindow(): void {
    this.partial = null
    this.openCalls.clear()
@@ -815,9 +827,7 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
        || metrics.projectionRevision < current.projectionRevision
      )
    ) return
-    this.metrics = this.contextWindow === undefined
-      ? metrics
-      : { ...metrics, contextWindow: this.contextWindow }
+    this.metrics = metrics
    this.notifier.markDirty()
  }

@@ -870,8 +880,10 @@ export class Session implements ObservableSnapshot<ConversationSnapshot> {
      promptError: this.promptError,
      blank: this.blankBit,
      lastAgentError: this.lastAgentError,
-      todos: this.todos,
      metrics: this.metrics,
+      ...(this.contextWindow === undefined
+        ? {}
+        : { modelRequestContextWindow: this.contextWindow }),
    }
  }
 }
--- a/packages/client/runtime/tests/event-script.ts
+++ b/packages/client/runtime/tests/event-script.ts
@@ -40,8 +40,10 @@ export const ev = {
    at(seq, { type: 'step/end', data: { turn, step } }),
  turnEnd: (seq: number, turn: number, reason: 'completed' | 'cancelled' = 'completed'): SessionEvent =>
    at(seq, { type: 'turn/end', data: { turn, reason: { kind: reason } } }),
-  todoWrite: (seq: number, todos: { content: string; status: 'pending' | 'in_progress' | 'completed' }[]): SessionEvent =>
-    at(seq, { type: 'todo/write', data: { todos } }),
+  commandRun: (seq: number, commandId: string, name: string, args = ''): SessionEvent =>
+    at(seq, { type: 'command/run', data: { commandId, name, args, source: { kind: 'user' } } }),
+  commandDone: (seq: number, commandId: string, kind: 'success' | 'error' = 'success', text?: string): SessionEvent =>
+    at(seq, { type: 'command/done', data: { commandId, kind, ...text === undefined ? {} : { text } } }),
 }

 /** One complete plain turn (turn/start → user → step → assistant → turn/end), 6 events from startSeq. */
--- a/packages/client/runtime/tests/fake-api.ts
+++ b/packages/client/runtime/tests/fake-api.ts
@@ -1,9 +1,11 @@
 // Test-local programmable IApiClient fake (NOT the fixture: fixture is a demo
 // data source on a real clock; behavior tests need per-case responses and
 // deferred-controlled timing). Streams are hand pumps: pushMux/pushHost.
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type {
-  ClientResponse, CommandDescriptor, CommandExecuteResult, HostFrame, IApiClient, ModelTarget, MuxFrame,
-  RpcError, RpcReceipt, RpcRequest, RpcResponse, SessionId, SessionMetrics, SessionModels, SkillEntry,
+  ClientResponse, CommandDescriptor, HostFrame, IApiClient, ModelTarget, MuxFrame,
+  RpcError, RpcReceipt, RpcRequest, RpcResponse, SessionId, SessionMetrics, SessionModels,
+  SessionProjectionsBlock, SkillEntry,
  WorkspaceId, WorkspaceView,
 } from '@deepseek-ai/dsh-client-connection/client'
 import { RpcId } from '@deepseek-ai/dsh-client-connection/client'
@@ -66,7 +68,7 @@ export class FakeApiClient implements IApiClient {
  => Promise<RpcResponse<{
    events: never[]
    hasMore: boolean
-    todos?: { content: string; status: 'pending' | 'in_progress' | 'completed' }[]
+    projections?: SessionProjectionsBlock
    metrics?: SessionMetrics
  }>> =
    () => Promise.resolve(ok({ events: [], hasMore: false }))
@@ -141,10 +143,12 @@ export class FakeApiClient implements IApiClient {
  // Payloads stay `unknown` (lint-lane note above); response rows are the real
  // wire shapes so cases can program requires-bearing catalogs and dual-address
  // skill lists without casts.
-  onCommandList: (payload: unknown) => Promise<RpcResponse<{ commands: CommandDescriptor[] }>> = () => Promise.resolve(ok({ commands: [] }))
-  onCommandExecute: (payload: unknown) => Promise<RpcResponse<{ matched: boolean; result?: CommandExecuteResult }>> =
-    () => Promise.resolve(ok({ matched: false }))
-  onSkillList: (payload: unknown) => Promise<RpcResponse<{ skills: SkillEntry[] }>> = () => Promise.resolve(ok({ skills: [] }))
+  onCommandList: (payload: unknown) => Promise<RpcResponse<{ commands: CommandDescriptor[] }>>
+    = () => Promise.resolve(ok({ commands: [] }))
+  onCommandExecute: (payload: unknown) => Promise<RpcResponse<{ matched: boolean; commandId?: CommandId }>>
+    = () => Promise.resolve(ok({ matched: false }))
+  onSkillList: (payload: unknown) => Promise<RpcResponse<{ skills: SkillEntry[] }>>
+    = () => Promise.resolve(ok({ skills: [] }))

  readonly commands: IApiClient['commands'] = {
    list: (payload: unknown) => this.record('command.list', payload, this.onCommandList(payload)),
--- a/packages/client/runtime/tests/fold-adapter.spec.ts
+++ b/packages/client/runtime/tests/fold-adapter.spec.ts
@@ -142,4 +142,75 @@ describe('FoldAdapter', () => {
    const node = adapter.nodes().nodes[0]
    expect(node).toMatchObject({ kind: 'tool-result', call: null, callView: null, resultView: { title: '孤儿' } })
  })
+
+  describe('command lifecycle nodes', () => {
+    it('folds a run/done pair into one settled node merged into flow order by seq', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([
+        ev.user(0, '先说话'),
+        ev.commandRun(1, 'cmd-1', 'plan'),
+        ev.commandDone(2, 'cmd-1', 'success', '已进入 plan mode'),
+        ev.assistant(3, 0, '然后回答'),
+      ], 0)
+      const { nodes } = adapter.nodes()
+      expect(nodes.map(n => [n.kind, n.seq])).toEqual([['user', 0], ['command', 1], ['assistant', 3]])
+      expect(nodes[1]).toMatchObject({
+        kind: 'command', commandId: 'cmd-1', name: 'plan', args: '',
+        outcome: { kind: 'success', text: '已进入 plan mode' },
+      })
+    })
+
+    it('renders a run with no done as still executing (outcome null)', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([ev.commandRun(0, 'cmd-2', 'goal', ' ship it')], 0)
+      expect(adapter.nodes().nodes[0]).toMatchObject({
+        kind: 'command', name: 'goal', args: ' ship it', outcome: null,
+      })
+    })
+
+    it('soft-falls a done-only window into a node built from the done (cross-window cut)', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([ev.commandDone(80, 'cmd-3', 'error', '失败了')], 80)
+      expect(adapter.nodes().nodes[0]).toMatchObject({
+        kind: 'command', seq: 80, commandId: 'cmd-3', name: null, args: null,
+        outcome: { kind: 'error', text: '失败了' },
+      })
+    })
+
+    it('settles a live-appended done in place, keeping the node at the run seq', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset(plainTurn(0, 0, 'q', 'a'), 0)
+      adapter.append(ev.commandRun(6, 'cmd-4', 'clear'))
+      const running = adapter.nodes().nodes.find(n => n.kind === 'command')
+      expect(running).toMatchObject({ outcome: null })
+      adapter.append(ev.commandDone(7, 'cmd-4'))
+      const settled = adapter.nodes().nodes.find(n => n.kind === 'command')
+      expect(settled).toMatchObject({ seq: 6, outcome: { kind: 'success' } })
+      // Settlement replaced the node object rather than mutating the published one.
+      expect(settled).not.toBe(running)
+    })
+
+    it('tails command nodes whose seq is past every surface node', () => {
+      const adapter = new FoldAdapter()
+      adapter.reset([ev.user(0, '问'), ev.commandRun(1, 'cmd-tail', 'plan')], 0)
+      expect(adapter.nodes().nodes.map(n => n.kind)).toEqual(['user', 'command'])
+    })
+
+    it('command nodes survive the degraded linear-scan branch', () => {
+      const adapter = new FoldAdapter()
+      const errorSpy = vi.spyOn(console, 'error').mockImplementation(() => undefined)
+      try {
+        adapter.reset([
+          ev.commandRun(0, 'cmd-5', 'plan'),
+          ev.commandDone(1, 'cmd-5'),
+          at(2, { type: 'assistant/message', surfaceOp: 'bogus-op', data: { turn: 0, step: 0, content: [{ type: 'text', text: '坏 op' }], provenance: { provider: 'x', model: 'y' } } }),
+        ], 0)
+        const { nodes, degraded } = adapter.nodes()
+        expect(degraded).toBe(true)
+        expect(nodes.some(n => n.kind === 'command')).toBe(true)
+      } finally {
+        errorSpy.mockRestore()
+      }
+    })
+  })
 })
--- a/packages/client/runtime/tests/manager.spec.ts
+++ b/packages/client/runtime/tests/manager.spec.ts
@@ -133,21 +133,18 @@ describe('list lifecycle', () => {
    expect(manager.getListSnapshot().items.map(i => i.sessionId)).toEqual([S2])
  })

-  it('retains monotonic title snapshots before list arrival, merges recency, and clears them on removal', async () => {
+  it('retains title projections before list arrival, keeps last-wins by seq, and clears them on removal', async () => {
    const api = new FakeApiClient()
    const manager = new SessionManager(api)
-    manager.handleMuxEnvelope({
-      rpcId: 'title-new' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Newest', eventSeq: 4, updatedAt: 300 },
-    })
-    manager.handleMuxEnvelope({
-      rpcId: 'title-stale' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Stale', eventSeq: 3, updatedAt: 900 },
-    })
-    manager.handleMuxEnvelope({
-      rpcId: 'title-equal' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Equal', eventSeq: 4, updatedAt: 901 },
-    })
+    const titleFrame = (rpcId: string, title: string, seq: number) => {
+      manager.handleMuxEnvelope({
+        rpcId: rpcId as never,
+        payload: { type: 'session/projection', sessionId: S1, key: 'title', value: title, seq } as never,
+      })
+    }
+    titleFrame('title-new', 'Newest', 4)
+    titleFrame('title-stale', 'Stale', 3)
+    titleFrame('title-equal', 'Equal', 4)
    api.onList = () => Promise.resolve(ok({
      items: [summary(S1), summary(S2, { updatedAt: 200 })] as never[],
    }))
@@ -155,7 +152,7 @@ describe('list lifecycle', () => {

    const titled = manager.getListSnapshot()
    expect(titled.items.map(item => item.sessionId)).toEqual([S1, S2])
-    expect(titled.items[0]).toMatchObject({ title: 'Newest', updatedAt: 300 })
+    expect(titled.items[0]?.title).toBe('Newest')
    expect(titled.items[1]?.title).toBeUndefined()

    manager.handleHostEnvelope({ rpcId: 'removed' as never, payload: { type: 'host/session-removed', sessionId: S1 } })
@@ -163,34 +160,27 @@ describe('list lifecycle', () => {
    expect(manager.getListSnapshot().items.find(item => item.sessionId === S1)?.title).toBeUndefined()
  })

-  it('drops a retained title beyond the subscription baseline before accepting its durable replay', async () => {
+  it('drops a projection row beyond the subscription baseline before accepting its durable replay', async () => {
    const api = new FakeApiClient()
    api.onList = () => Promise.resolve(ok({ items: [summary(S1)] as never[] }))
    const manager = new SessionManager(api)
    await manager.refreshList()
-    manager.handleMuxEnvelope({
-      rpcId: 'title-unflushed' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Unflushed', eventSeq: 4, updatedAt: 400 },
-    })
+    const frame = (rpcId: string, payload: object) => {
+      manager.handleMuxEnvelope({ rpcId: rpcId as never, payload: payload as never })
+    }
+    frame('title-unflushed', { type: 'session/projection', sessionId: S1, key: 'title', value: 'Unflushed', seq: 4 })

-    manager.handleMuxEnvelope({
-      rpcId: 'subscribed-recovered' as never,
-      payload: { type: 'session/subscribed', sessionId: S1, lastSeq: 2 },
-    })
+    // The durable baseline says the host only knows up to seq 2: the phantom
+    // row rode lost state and must drop, or last-wins pins it forever.
+    frame('subscribed-recovered', { type: 'session/subscribed', sessionId: S1, lastSeq: 2 })
    expect(manager.getListSnapshot().items[0]?.title).toBeUndefined()
-    expect(manager.getListSnapshot().items[0]?.updatedAt).toBe(100)

-    manager.handleMuxEnvelope({
-      rpcId: 'title-durable' as never,
-      payload: { type: 'session/title', sessionId: S1, title: 'Durable', eventSeq: 2, updatedAt: 200 },
-    })
-    expect(manager.getListSnapshot().items[0]).toMatchObject({ title: 'Durable', updatedAt: 200 })
+    frame('title-durable', { type: 'session/projection', sessionId: S1, key: 'title', value: 'Durable', seq: 2 })
+    expect(manager.getListSnapshot().items[0]?.title).toBe('Durable')

-    manager.handleMuxEnvelope({
-      rpcId: 'subscribed-current' as never,
-      payload: { type: 'session/subscribed', sessionId: S1, lastSeq: 2 },
-    })
-    expect(manager.getListSnapshot().items[0]).toMatchObject({ title: 'Durable', updatedAt: 200 })
+    // A baseline at or past the row's seq keeps it (nothing phantom to drop).
+    frame('subscribed-current', { type: 'session/subscribed', sessionId: S1, lastSeq: 2 })
+    expect(manager.getListSnapshot().items[0]?.title).toBe('Durable')
  })
 })

--- a/packages/client/runtime/tests/projection-store.spec.ts
+++ b/packages/client/runtime/tests/projection-store.spec.ts
@@ -0,0 +1,187 @@
+/**
+ * Projection value store (session-projection RFC, push model): the single
+ * higher-seq-wins rule on both paths (a stale baseline cannot overwrite a
+ * newer push frame; a replayed frame cannot regress), capability absence as
+ * undefined, generation truncation, and the Session/manager wiring (tail-page
+ * seeding, session/projection frame routing pre- and post-instantiation, the
+ * list rows' title projection).
+ */
+import { describe, expect, it } from 'vitest'
+import type { SessionId } from '@deepseek-ai/dsh-client-connection/client'
+import { ProjectionValueStore } from '../src/client/sessions/projection-store.ts'
+import { Session } from '../src/client/sessions/session.ts'
+import { SessionManager } from '../src/client/sessions/manager.ts'
+import { FakeApiClient, ok } from './fake-api.ts'
+import { entries, plainTurn } from './event-script.ts'
+
+// Test-domain keys merged into the projection map (the interface package's
+// pure-type outlet), the same way domain host plugins merge theirs.
+declare module '@deepseek-ai/dsh-session-projection/types' {
+  interface SessionProjectionMap {
+    'test/marks': { marks: string[] }
+  }
+}
+
+const SID = 'fk-s1' as SessionId
+
+describe('ProjectionValueStore semantics', () => {
+  it('reads undefined until a value lands (capability absence)', () => {
+    const store = new ProjectionValueStore()
+    expect(store.get('test/marks')).toBeUndefined()
+    expect(store.faceOf('test/marks').getSnapshot()).toBeUndefined()
+  })
+
+  it('applies frames last-wins by seq: replayed and stale frames drop', () => {
+    const store = new ProjectionValueStore()
+    store.apply('test/marks', { marks: ['a'] }, 5)
+    store.apply('test/marks', { marks: ['a', 'b'] }, 9)
+    expect(store.get('test/marks')).toEqual({ marks: ['a', 'b'] })
+    store.apply('test/marks', { marks: ['stale'] }, 5)
+    store.apply('test/marks', { marks: ['equal'] }, 9)
+    expect(store.get('test/marks')).toEqual({ marks: ['a', 'b'] })
+  })
+
+  it('a stale baseline can neither overwrite nor clear a newer frame; a fresh one reseeds and clears', () => {
+    const store = new ProjectionValueStore()
+    store.apply('test/marks', { marks: ['frame-20'] }, 20)
+    // Stale cut: carried key loses to the newer frame; omitted key survives.
+    store.seed({ asOfSeq: 10, values: { 'test/marks': { marks: ['baseline-10'] } } })
+    expect(store.get('test/marks')).toEqual({ marks: ['frame-20'] })
+    store.seed({ asOfSeq: 15, values: {} })
+    expect(store.get('test/marks')).toEqual({ marks: ['frame-20'] })
+    // Fresh cut: carried key reseeds…
+    store.seed({ asOfSeq: 30, values: { 'test/marks': { marks: ['baseline-30'] } } })
+    expect(store.get('test/marks')).toEqual({ marks: ['baseline-30'] })
+    // …and an omitting fresh cut clears (capability absent as of the cut).
+    store.seed({ asOfSeq: 40, values: {} })
+    expect(store.get('test/marks')).toBeUndefined()
+  })
+
+  it('truncate drops rows past the durable baseline and keeps the rest', () => {
+    const store = new ProjectionValueStore()
+    store.apply('test/marks', { marks: ['durable'] }, 5)
+    store.apply('other', 'phantom', 50)
+    store.truncate(10)
+    expect(store.get('test/marks')).toEqual({ marks: ['durable'] })
+    expect(store.get('other')).toBeUndefined()
+  })
+
+  it('notifies the key face on change (batched) and not on dropped applications', async () => {
+    const store = new ProjectionValueStore()
+    let keyTicks = 0
+    let anyTicks = 0
+    store.faceOf('test/marks').subscribe(() => { keyTicks += 1 })
+    store.subscribeAny(() => { anyTicks += 1 })
+    store.apply('test/marks', { marks: ['a'] }, 5)
+    await Promise.resolve()
+    expect(keyTicks).toBe(1)
+    expect(anyTicks).toBe(1)
+    store.apply('test/marks', { marks: ['replay'] }, 3)
+    await Promise.resolve()
+    expect(keyTicks).toBe(1)
+    expect(anyTicks).toBe(1)
+  })
+
+  it('faces are identity-stable per key (the React binding cache premise)', () => {
+    const store = new ProjectionValueStore()
+    expect(store.faceOf('test/marks')).toBe(store.faceOf('test/marks'))
+  })
+})
+
+describe('Session tail-page seeding', () => {
+  it('seeds the store from a history response carrying a projections block', async () => {
+    const api = new FakeApiClient()
+    const session = new Session(SID, api)
+    api.onHistory = () => Promise.resolve(ok({
+      events: entries(plainTurn(0, 0, '问', '答')) as never[], hasMore: false,
+      projections: { asOfSeq: 5, values: { 'test/marks': { marks: ['from-baseline'] } } },
+    } as never))
+    await session.open()
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['from-baseline'] })
+  })
+
+  it('a resync serving a stale block keeps the newer pushed value (seq rule end to end)', async () => {
+    const api = new FakeApiClient()
+    const session = new Session(SID, api)
+    api.onHistory = () => Promise.resolve(ok({
+      events: entries(plainTurn(0, 0, 'a', 'b')) as never[], hasMore: false,
+      projections: { asOfSeq: 5, values: { 'test/marks': { marks: ['baseline'] } } },
+    } as never))
+    await session.open()
+    session.projections.apply('test/marks', { marks: ['pushed-9'] }, 9)
+    await session.resync()
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['pushed-9'] })
+  })
+
+  it('treats a blockless response as no reset: pushed values survive', async () => {
+    const api = new FakeApiClient()
+    const session = new Session(SID, api)
+    api.onHistory = () => Promise.resolve(ok({ events: entries(plainTurn(0, 0, 'a', 'b')) as never[], hasMore: false }))
+    await session.open()
+    session.projections.apply('test/marks', { marks: ['pushed'] }, 9)
+    await session.resync()
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['pushed'] })
+  })
+})
+
+describe('manager frame routing', () => {
+  const sid = (s: string): SessionId => s as SessionId
+
+  it('lands session/projection frames before instantiation and the Session adopts the same store', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    manager.handleMuxEnvelope({
+      rpcId: 'p1' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'test/marks', value: { marks: ['early'] }, seq: 7 } as never,
+    })
+    const session = manager.get(sid('s1'))
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['early'] })
+    // Frames after instantiation land in the same store.
+    manager.handleMuxEnvelope({
+      rpcId: 'p2' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'test/marks', value: { marks: ['later'] }, seq: 9 } as never,
+    })
+    expect(session.projections.get('test/marks')).toEqual({ marks: ['later'] })
+  })
+
+  it('projects the title key into list rows and truncates phantom rows on the subscribed baseline', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    api.onList = () => Promise.resolve(ok({
+      items: [{ sessionId: sid('s1'), updatedAt: 1, running: false, blank: false }],
+    }) as never)
+    await manager.refreshList()
+    manager.handleMuxEnvelope({
+      rpcId: 't1' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'title', value: 'Projected title', seq: 4 } as never,
+    })
+    await Promise.resolve()
+    expect(manager.getListSnapshot().items[0]?.title).toBe('Projected title')
+    // The durable baseline says the host only knows up to seq 2: the row rode
+    // lost state and must drop (the un-flushed title precedent).
+    manager.handleMuxEnvelope({
+      rpcId: 'sub' as never,
+      payload: { type: 'session/subscribed', sessionId: sid('s1'), lastSeq: 2 } as never,
+    })
+    await Promise.resolve()
+    expect(manager.getListSnapshot().items[0]?.title).toBeUndefined()
+  })
+
+  it('drops the projection store with the removed session', async () => {
+    const api = new FakeApiClient()
+    const manager = new SessionManager(api)
+    api.onList = () => Promise.resolve(ok({
+      items: [{ sessionId: sid('s1'), updatedAt: 1, running: false, blank: false }],
+    }) as never)
+    await manager.refreshList()
+    manager.handleMuxEnvelope({
+      rpcId: 't1' as never,
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'title', value: 'Doomed', seq: 4 } as never,
+    })
+    manager.handleHostEnvelope({
+      rpcId: 'rm' as never,
+      payload: { type: 'host/session-removed', sessionId: sid('s1') } as never,
+    })
+    expect(manager.get(sid('s1')).projections.get('title')).toBeUndefined()
+  })
+})
--- a/packages/client/runtime/tests/session.spec.ts
+++ b/packages/client/runtime/tests/session.spec.ts
@@ -9,7 +9,9 @@
 import { describe, expect, it, vi } from 'vitest'
 import { Context } from 'cordis'
 import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
-import type { SessionId, SessionMetrics } from '@deepseek-ai/dsh-client-connection/client'
+import type {
+  SessionId, SessionMetrics, SessionProjectionsBlock,
+} from '@deepseek-ai/dsh-client-connection/client'
 import { Session } from '../src/client/sessions/session.ts'
 import { FakeApiClient, deferred, err, ok } from './fake-api.ts'
 import { entries, ev, plainTurn } from './event-script.ts'
@@ -26,14 +28,14 @@ function makeSession(api = new FakeApiClient()): { api: FakeApiClient; session:
 function histResponse(
  events: SessionEvent[],
  hasMore = false,
-  todos?: { content: string; status: 'pending' | 'in_progress' | 'completed' }[],
+  projections?: SessionProjectionsBlock,
  metrics?: SessionMetrics,
 ) {
  // history now returns HistoryEntry[] ({event, view?}); these tests are view-less.
  return Promise.resolve(ok({
    events: entries(events) as never[],
    hasMore,
-    ...todos === undefined ? {} : { todos },
+    ...projections === undefined ? {} : { projections },
    ...metrics === undefined ? {} : { metrics },
  }))
 }
@@ -145,7 +147,7 @@ describe('live event path', () => {
    expect(session.getSnapshot().nodes).toEqual(before.nodes)
  })

-  it('retains live capacity across metrics, replaces or clears it on requests, and resets at subscription', async () => {
+  it('keeps live capacity separate from durable metrics, replaces or clears it on requests, and resets at subscription', async () => {
    const { session } = await opened()
    const current = metrics(8, 10)
    session.handleMuxEnvelope('m1' as never, {
@@ -154,6 +156,7 @@ describe('live event path', () => {
      metrics: current,
    })
    expect(session.getSnapshot().metrics).toBe(current)
+    expect(session.getSnapshot().modelRequestContextWindow).toBeUndefined()

    session.handleMuxEnvelope('request-1' as never, {
      type: 'session/model-request',
@@ -164,10 +167,8 @@ describe('live event path', () => {
      model: 'alpha',
      contextWindow: 128_000,
    })
-    expect(session.getSnapshot().metrics).toEqual({
-      ...current,
-      contextWindow: 128_000,
-    })
+    expect(session.getSnapshot().metrics).toBe(current)
+    expect(session.getSnapshot().modelRequestContextWindow).toBe(128_000)

    session.handleMuxEnvelope('m2' as never, {
      type: 'session/metrics',
@@ -179,10 +180,8 @@ describe('live event path', () => {
      sessionId: SID,
      metrics: metrics(7, 11, { uncachedInputTokens: 2 }),
    })
-    expect(session.getSnapshot().metrics).toEqual({
-      ...current,
-      contextWindow: 128_000,
-    })
+    expect(session.getSnapshot().metrics).toBe(current)
+    expect(session.getSnapshot().modelRequestContextWindow).toBe(128_000)

    const ordinaryUpdate = metrics(9, 11, { contextTokens: 40 })
    session.handleMuxEnvelope('m4' as never, {
@@ -190,10 +189,8 @@ describe('live event path', () => {
      sessionId: SID,
      metrics: ordinaryUpdate,
    })
-    expect(session.getSnapshot().metrics).toEqual({
-      ...ordinaryUpdate,
-      contextWindow: 128_000,
-    })
+    expect(session.getSnapshot().metrics).toBe(ordinaryUpdate)
+    expect(session.getSnapshot().modelRequestContextWindow).toBe(128_000)

    session.handleMuxEnvelope('request-2' as never, {
      type: 'session/model-request',
@@ -204,6 +201,7 @@ describe('live event path', () => {
      model: 'without-capacity',
    })
    expect(session.getSnapshot().metrics).toEqual(ordinaryUpdate)
+    expect(session.getSnapshot().modelRequestContextWindow).toBeUndefined()

    session.handleMuxEnvelope('sub' as never, {
      type: 'session/subscribed',
@@ -211,6 +209,7 @@ describe('live event path', () => {
      lastSeq: 5,
    })
    expect(session.getSnapshot().metrics).toBeNull()
+    expect(session.getSnapshot().modelRequestContextWindow).toBeUndefined()
    session.handleMuxEnvelope('request-3' as never, {
      type: 'session/model-request',
      sessionId: SID,
@@ -226,9 +225,51 @@ describe('live event path', () => {
      sessionId: SID,
      metrics: nextGeneration,
    })
-    expect(session.getSnapshot().metrics).toEqual({
-      ...nextGeneration,
-      contextWindow: 256_000,
+    expect(session.getSnapshot().metrics).toBe(nextGeneration)
+    expect(session.getSnapshot().modelRequestContextWindow).toBe(256_000)
+  })
+
+  it('publishes a subscribed reset when capacity arrived before durable metrics', async () => {
+    const { session } = await opened()
+    session.handleMuxEnvelope('request' as never, {
+      type: 'session/model-request',
+      sessionId: SID,
+      turn: 1,
+      step: 1,
+      provider: 'test',
+      model: 'alpha',
+      contextWindow: 128_000,
+    })
+    expect(session.getSnapshot().metrics).toBeNull()
+    expect(session.getSnapshot().modelRequestContextWindow).toBe(128_000)
+
+    session.handleMuxEnvelope('sub' as never, {
+      type: 'session/subscribed',
+      sessionId: SID,
+      lastSeq: 5,
+    })
+    expect(session.getSnapshot().modelRequestContextWindow).toBeUndefined()
+  })
+
+  it('materializes a command node from live lifecycle frames and reproduces it from a history window', async () => {
+    // Live path: run mints an executing node, done settles it in the flow.
+    const { session } = await opened()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.commandRun(6, 'cmd-live', 'plan'))
+    let command = session.getSnapshot().nodes.at(-1)
+    expect(command).toMatchObject({ kind: 'command', name: 'plan', args: '', outcome: null })
+    feed(ev.commandDone(7, 'cmd-live', 'success', '已进入 plan mode'))
+    command = session.getSnapshot().nodes.at(-1)
+    expect(command).toMatchObject({ kind: 'command', seq: 6, outcome: { kind: 'success', text: '已进入 plan mode' } })
+
+    // Replay path (refresh): the same pair inside the history window folds identically.
+    const replayed = await opened([
+      ...plainTurn(0, 0, 'a', 'b'),
+      ev.commandRun(6, 'cmd-live', 'plan'),
+      ev.commandDone(7, 'cmd-live', 'success', '已进入 plan mode'),
+    ])
+    expect(replayed.session.getSnapshot().nodes.at(-1)).toMatchObject({
+      kind: 'command', seq: 6, name: 'plan', outcome: { kind: 'success', text: '已进入 plan mode' },
    })
  })

@@ -286,42 +327,6 @@ describe('live event path', () => {
    })
  })

-  it('folds todo/write into snapshot.todos last-write-wins, live and on window replay', async () => {
-    const listA = [{ content: '搭骨架', status: 'completed' as const }, { content: '写组件', status: 'in_progress' as const }]
-    const listB = [{ content: '搭骨架', status: 'completed' as const }, { content: '写组件', status: 'completed' as const }]
-    const { session } = await opened()
-    expect(session.getSnapshot().todos).toEqual([])
-    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
-    feed(ev.todoWrite(6, listA))
-    expect(session.getSnapshot().todos).toEqual(listA)
-    feed(ev.todoWrite(7, listB))
-    expect(session.getSnapshot().todos).toEqual(listB)
-    // Window replay converges on the same last snapshot (history contains both writes).
-    const replayed = makeSession()
-    replayed.api.onHistory = () => histResponse([...plainTurn(0, 0, 'a', 'b'), ev.todoWrite(6, listA), ev.todoWrite(7, listB)])
-    await replayed.session.open()
-    expect(replayed.session.getSnapshot().todos).toEqual(listB)
-  })
-
-  it('seeds todos from the tail page projection when the last write precedes the window', async () => {
-    const list = [{ content: '窗口外的计划', status: 'in_progress' as const }]
-    // Cold open: the page window carries NO todo/write; the projection rides the response.
-    const { api, session } = makeSession()
-    api.onHistory = () => histResponse(plainTurn(100, 9, '问', '答'), true, list)
-    await session.open()
-    expect(session.getSnapshot().todos).toEqual(list)
-    // Paging an older window in must not clear the session-level projection.
-    api.onHistory = () => histResponse(plainTurn(94, 8, '旧问', '旧答'), false)
-    await session.loadOlder()
-    expect(session.getSnapshot().todos).toEqual(list)
-    // A later live write still overrides the seeded projection.
-    session.handleMuxEnvelope('r' as never, {
-      type: 'session/event', sessionId: SID,
-      event: ev.todoWrite(106, [{ content: '新计划', status: 'pending' as const }]),
-    })
-    expect(session.getSnapshot().todos).toEqual([{ content: '新计划', status: 'pending' }])
-  })
-
  it('repairs a seq gap by repulling the tail page instead of appending a hole', async () => {
    const { api, session } = await opened(plainTurn(0, 0, 'a', 'b')) // tail seq = 5
    const repaired = [...plainTurn(0, 0, 'a', 'b'), ...plainTurn(6, 1, 'c', 'd')]
@@ -335,37 +340,6 @@ describe('live event path', () => {
    const seqs = session.getSnapshot().nodes.map(n => n.seq)
    expect(seqs).toEqual([1, 3, 7, 9]) // both turns' user/assistant, no hole, no duplicate 9
  })
-
-  it('gap repair adopts the repull response projection (a missed todo/write outside the new tail page)', async () => {
-    const { api, session } = await opened(plainTurn(0, 0, 'a', 'b')) // tail seq = 5
-    expect(session.getSnapshot().todos).toEqual([])
-    // The missed range contained a todo/write that the repulled page no longer
-    // covers; the response's session-level projection is the only carrier.
-    const current = [{ content: '断线期间写的', status: 'in_progress' as const }]
-    api.onHistory = () => histResponse([...plainTurn(0, 0, 'a', 'b'), ...plainTurn(8, 1, 'c', 'd')], false, current)
-    session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event: ev.assistant(11, 1, 'd') })
-    await vi.waitFor(() => {
-      expect(api.callsOf('session.history').length).toBe(2)
-    })
-    await Promise.resolve()
-    expect(session.getSnapshot().todos).toEqual(current)
-  })
-
-  it('clears the plan when a tail response omits the projection (a write the log never kept)', async () => {
-    // Live write lands, then the host crashes before persisting it: the
-    // authoritative log holds no todo/write, so the resync tail response
-    // carries no projection — an omitted field on a tail request is the empty
-    // list, not a missing carrier, and the rolled-back plan must disappear.
-    const { api, session } = await opened(plainTurn(0, 0, 'a', 'b'))
-    session.handleMuxEnvelope('r' as never, {
-      type: 'session/event', sessionId: SID,
-      event: ev.todoWrite(6, [{ content: '丢失的计划', status: 'in_progress' as const }]),
-    })
-    expect(session.getSnapshot().todos).toEqual([{ content: '丢失的计划', status: 'in_progress' }])
-    api.onHistory = () => histResponse(plainTurn(0, 0, 'a', 'b'))
-    await session.resync()
-    expect(session.getSnapshot().todos).toEqual([])
-  })
 })

 describe('paging', () => {
--- a/packages/client/runtime/tests/sessions-service.spec.ts
+++ b/packages/client/runtime/tests/sessions-service.spec.ts
@@ -47,7 +47,7 @@ describe('list store projection', () => {
    const b = bench()
    b.svc.handleMuxEnvelope({
      rpcId: 'title' as never,
-      payload: { type: 'session/title', sessionId: sid('s1'), title: 'Durable title', eventSeq: 2, updatedAt: 3 },
+      payload: { type: 'session/projection', sessionId: sid('s1'), key: 'title', value: 'Durable title', seq: 2 } as never,
    })
    await feedList(b, [
      { id: 's1', cwd: '/home/u/proj-a/' },
--- a/packages/client/runtime/tsconfig.json
+++ b/packages/client/runtime/tsconfig.json
@@ -23,6 +23,15 @@
    {
      "path": "../../host/apiproxy"
    },
+    {
+      "path": "../../ui/commands"
+    },
+    {
+      "path": "../../session-projection/session-projection"
+    },
+    {
+      "path": "../../session-title/session-title"
+    },
    {
      "path": "../../llm/llm"
    },
--- a/packages/client/ui-command/src/client/PopupSelectView.module.css
+++ b/packages/client/ui-command/src/client/PopupSelectView.module.css
@@ -15,6 +15,10 @@
  min-width: 220px;
  max-height: 320px;
  overflow-y: auto;
+  /* Elevated surface: the scrollbar thumb takes the l2 elevation tokens
+     (see ui-theme styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
  border: 1px solid var(--dsw-alias-border-inverted);
  border-radius: 12px;
  background: var(--dsw-specific-menu);
--- a/packages/client/ui-command/src/client/service.ts
+++ b/packages/client/ui-command/src/client/service.ts
@@ -227,7 +227,15 @@ export class CommandService extends Service implements CommandServiceContract {
    }
  }

-  /** The command.execute transaction, addressed to the session's agent. */
+  /**
+   * The command.execute transaction, addressed to the session's agent — pure
+   * admission semantics. An unmatched line reports an error outcome (the
+   * composer's immediate admission feedback); an admitted command reports
+   * plain success regardless of its handler outcome, because the host
+   * executor durably logged the lifecycle (`command/run`/`command/done`) and
+   * the outcome renders as a persistent flow node — the composer never
+   * echoes it. Transport failures throw.
+   */
  private async execute(
    session: ClientSessionContext,
    line: string,
@@ -236,25 +244,25 @@ export class CommandService extends Service implements CommandServiceContract {
    const { result } = await connection.api.commands.execute({ sessionId: session.sessionId, line })
    if (!result.ok) throw new Error(`command.execute failed: ${result.error.code}: ${result.error.message}`)
    if (!result.value.matched) return { kind: 'error', text: `unknown or malformed command: ${line}` }
-    const detached = result.value.result
-    return detached === undefined
-      ? { kind: 'success' }
-      : { kind: detached.kind, ...(detached.text !== undefined ? { text: detached.text } : {}) }
+    return { kind: 'success' }
  }

  /**
-   * Fire-and-forget execute for the internal ('handled') paths. The detached
-   * result surfaces as a notice routed to the triggering session's composer,
-   * so a late result lands on its own session after a switch.
+   * Fire-and-forget execute for the internal ('handled') paths. Outcomes are
+   * NOT surfaced here: the host executor durably logs the command lifecycle
+   * (`command/run`/`command/done`), and the mux-broadcast events render as a
+   * persistent flow node on every tab. Only a transport/admission failure —
+   * which never entered a handler and therefore never logged — falls back to
+   * the composer notice as immediate feedback.
   */
  private runDetached(desc: CommandDescriptor, session: ClientSessionContext, line: string): void {
    void this.execute(session, line).then(
      (outcome) => {
-        if (outcome.kind === 'error') this.noticeFor(session.sessionId, desc.name, 'error', outcome.text ?? `/${desc.name} failed`)
-        else if (outcome.text !== undefined) this.noticeFor(session.sessionId, desc.name, 'info', outcome.text)
+        // matched:false maps to an error outcome with no logged lifecycle.
+        if (outcome.kind === 'error') this.noticeFor(session.sessionId, 'error', outcome.text ?? `/${desc.name} failed`)
      },
      (error: unknown) => {
-        this.noticeFor(session.sessionId, desc.name, 'error', error instanceof Error ? error.message : String(error))
+        this.noticeFor(session.sessionId, 'error', error instanceof Error ? error.message : String(error))
      },
    )
  }
@@ -270,8 +278,8 @@ export class CommandService extends Service implements CommandServiceContract {
    })
  }

-  /** Route a detached result to the session's composer notice channel (scope gone = attempt died with it). */
-  private noticeFor(id: SessionId, _name: string, level: 'info' | 'error', text: string): void {
+  /** Route an admission/transport failure to the session's composer notice channel (scope gone = attempt died with it). */
+  private noticeFor(id: SessionId, level: 'info' | 'error', text: string): void {
    const actx = this.scopeFor(id)
    if (actx === undefined) return
    const conversation = actx.get('conversation')
--- a/packages/client/ui-command/tests/service.spec.ts
+++ b/packages/client/ui-command/tests/service.spec.ts
@@ -31,7 +31,7 @@ const S2_CMDS: CommandDescriptor[] = [
  { name: 'attach', description: 'scoped shadow', input: { hint: 'path' } },
 ]

-type ExecuteValue = { matched: boolean; result?: { kind: 'success' | 'error'; text?: string } }
+type ExecuteValue = { matched: boolean }

 interface BenchOptions {
  /** Scripted catalog per list payload; default serves the fixed catalogs by session. */
@@ -361,16 +361,18 @@ describe('matchEnter (enter column)', () => {
 })

 describe('execute payload', () => {
-  it('claim.submit addresses the session and maps the detached result', async () => {
+  it('claim.submit addresses the session; admitted outcomes stay off the composer (flow card owns them)', async () => {
    const { source, warm, executeCalls } = await bench({
-      execute: () => Promise.resolve({ matched: true, result: { kind: 'success', text: 'goal set' } }),
+      execute: () => Promise.resolve({ matched: true }),
    })
    await warm(proj('s1'))
    const outcome = source.matchSpace!(proj('s1'), '/goal')
    if (outcome === undefined || outcome === 'handled' || !('claim' in outcome)) throw new Error('expected claim')
    const settled = await outcome.claim.submit('ship it', new Context())
    expect(executeCalls).toEqual([{ sessionId: sid('s1'), line: '/goal ship it' }])
-    expect(settled).toEqual({ kind: 'success', text: 'goal set' })
+    // Pure admission: no outcome text ever rides the submit result — the
+    // durable command lifecycle events render the outcome in the flow.
+    expect(settled).toEqual({ kind: 'success' })
  })

  it('maps matched:false to an error outcome and a matched bare result to success', async () => {
@@ -389,33 +391,29 @@ describe('execute payload', () => {
  })
 })

-describe('detached result notices', () => {
+describe('detached admission notices', () => {
  const flush = () => new Promise(resolve => setTimeout(resolve, 0))

-  it('success text → info; error result → error; rejection → error, all on the triggering session', async () => {
-    let mode: 'info' | 'error' | 'reject' = 'info'
+  it('admitted outcomes stay silent; admission miss and transport rejection notice as errors', async () => {
+    let mode: 'admitted' | 'miss' | 'reject' = 'admitted'
    const { source, mint, warm, notices } = await bench({
      execute: () => {
        if (mode === 'reject') return Promise.reject(new Error('network down'))
-        return Promise.resolve({
-          matched: true,
-          result: mode === 'info'
-            ? { kind: 'success' as const, text: 'compacted 12 messages' }
-            : { kind: 'error' as const, text: 'plan mode refused' },
-        })
+        return Promise.resolve({ matched: mode === 'admitted' })
      },
    })
    mint('s1')
    await warm(proj('s1'))
+    // Admitted: the durable lifecycle events own the outcome — no notice.
    menuPick(source, 'plan', proj('s1'))
    await flush()
-    expect(notices).toEqual([{ scope: sid('s1'), level: 'info', text: 'compacted 12 messages' }])
+    expect(notices).toEqual([])

-    notices.length = 0
-    mode = 'error'
+    // Admission miss (matched:false): immediate composer feedback stays.
+    mode = 'miss'
    await source.matchEnter!(proj('s1'), '/plan', new AbortController().signal)
    await flush()
-    expect(notices).toEqual([{ scope: sid('s1'), level: 'error', text: 'plan mode refused' }])
+    expect(notices).toEqual([{ scope: sid('s1'), level: 'error', text: 'unknown or malformed command: /plan' }])

    notices.length = 0
    mode = 'reject'
@@ -424,9 +422,9 @@ describe('detached result notices', () => {
    expect(notices).toEqual([{ scope: sid('s1'), level: 'error', text: 'network down' }])
  })

-  it('success without text stays silent; a torn-down scope drops the notice', async () => {
+  it('a torn-down scope drops the failure notice', async () => {
    const { source, warm, notices } = await bench({
-      execute: () => Promise.resolve({ matched: true, result: { kind: 'success' as const, text: 'orphan' } }),
+      execute: () => Promise.reject(new Error('orphan failure')),
    })
    await warm(proj('ghost')) // never minted: scopeFor misses
    menuPick(source, 'plan', proj('ghost'))
--- a/packages/client/ui-conversation/README.i18n.yaml
+++ b/packages/client/ui-conversation/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-conversation/README.md
-README.md: 1f47260f9034f22ba560552e5a99b938bf14ed6d
-README.zh.md: 7d9a9d2ab95d93668de216d64eee704bcc569547
+README.md: 15bc7c8e18f9992d6c2f0e9770ae33504399266d
+README.zh.md: 1775990359db16adfdd087363bc265aac569799f
--- a/packages/client/ui-conversation/README.md
+++ b/packages/client/ui-conversation/README.md
@@ -12,13 +12,13 @@ Generic tool rows classify the built-in bash, read, search, write, edit, and run

 Tool rows are slots too — the standalone tool ring (`ToolViewRegistry`/`ctx.toolviews`/outlet) is retired. The chat entry declares the keyed `'conversation.chat.toolview'` hole (session scope; the key space is runtime-open); its render site dispatches per row via `entryKey: toolName` with `GenericToolCard` as the call-site `fallback`. The owner payload is the uniform `ToolRowOwnerProps` (`callId`/`toolName`/`block`/`openFile`) and `ToolRowProps` pre-composes it with the session standard kit. A registrant is a plain plugin: `ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)` with `inject: ['slots', 'conversation']` as the load-order seam (apply mounts ConversationService after the chat registration, so the service being present guarantees the slot is declared); session differentiation happens inside the component (`useSessions` reading `parentId` — the bash sample is the third-party-posture exemplar). Trajectory/waterfall toolview slots share this shape and land with their own render sites (RendersCheck rejects a declaration nobody renders).

-The todo surfaces are two registrations over that shape, both plain registrant plugins with `inject: ['slots', 'conversation']`. `TodoRow` takes the `'conversation.chat.toolview'` key `todo_write` and summarizes what the call attempted (`<done>/<total> 已完成 · <active item>` parsed from its args, falling back to the generic summary on malformed or wrongly-shaped model JSON, and keeping the generic dot for non-ok execution states so a cancelled call never reads as a completed update). `TodoDock` takes the `'conversation.input.dock'` list slot at `order: -1` — above the queue rows — and is the durable plan strip: it selects `todos` off the session snapshot and renders `TodoPanel`, which takes the plain list, hides itself while the list is empty, and collapses to a header of title plus `"<done>/<total> tasks · <n> in progress"` (status glyphs are the figma check / progress / dashed-pending set). The dock adapter owns the selection so the panel stays a pure function of its props; the persistent list lives here rather than in the row so the row stays one line. Anything the input-zone composer chain hides (a `conversation.composer` takeover such as ui-question's) hides the whole dock, this strip included.
+The todo surfaces are two registrations over that shape, both plain registrant plugins with `inject: ['slots', 'conversation']`. `TodoRow` takes the `'conversation.chat.toolview'` key `todo_write` and summarizes what the call attempted (`<done>/<total> 已完成 · <active item>` parsed from its args, falling back to the generic summary on malformed or wrongly-shaped model JSON, and keeping the generic dot for non-ok execution states so a cancelled call never reads as a completed update). `TodoDock` takes the `'conversation.input.dock'` list slot at `order: -1` — above the queue rows — and is the durable plan strip: it reads the Host-computed `todos` key through `useProjection` and renders `TodoPanel`, which takes the plain list, hides itself while the list is empty, and collapses to a header of title plus `"<done>/<total> tasks · <n> in progress"` (status glyphs are the figma check / progress / dashed-pending set). The dock adapter owns the selection so the panel stays a pure function of its props; the persistent list lives here rather than in the row so the row stays one line. Anything the input-zone composer chain hides (a `conversation.composer` takeover such as ui-question's) hides the whole dock, this strip included.

 Per-session UI state for selection and the active view lives in the declared chat store (`stores.ts` `createChatStore`); the InputHub owns the composer state machine and mirrors its draft into that store for persistence. Apply passes one store handle to the strict session subtree, chat view, and details registrations, so each session shares one instance and the framework owns its lifecycle. Components are pure: the framework standard kit supplies `useSession`/`sessionId`, global `useSessions`/`useWorkspaces`, and the input machine's `useInput`/`inputActions`; store faces and inject factories supply the remaining state and callbacks.

 The composer bar declares session-scoped single seats for `'conversation.input.plan'` and `'conversation.input.model'`, plus list slots for overlay, dock, left, and right input extensions. InputBar renders the model seat immediately before its pending indicator and send/stop button. Feature packages own each control and its state; ui-conversation supplies placement, the `locked` owner prop, and the standard slot shares. The resident no-session shell uses `DisabledInputBar` and therefore dispatches no session-scoped control seats.

-The chat stats line reads durable token counters/current pressure plus the runtime's connection-local capacity overlay only from `ConversationSnapshot.metrics`; visible nodes supply only the existing turn/step counts. It renders uncached input, output, and cache reads as separate compact values, computes cache hit as `cacheRead / (uncachedInput + cacheRead)` without cache writes, and shows context occupancy only after the current mux connection observes a model request with capacity. Before that request, after reconnect/restore/new subscription, or after a request without capacity, the percentage is omitted and context is labeled unknown rather than queried ahead or reconstructed from history.
+The chat stats line reads durable token counters/current pressure from `ConversationSnapshot.metrics` and joins them only at presentation with the separate connection-local `modelRequestContextWindow`; visible nodes supply only the existing turn/step counts. It renders uncached input, output, and cache reads as separate compact values, computes cache hit as `cacheRead / (uncachedInput + cacheRead)` without cache writes, and shows context occupancy only after the current mux connection observes a model request with capacity. Before that request, after reconnect/restore/new subscription, or after a request without capacity, the percentage is omitted and context is labeled unknown rather than queried ahead or reconstructed from history.

 `src/client/` is organized for the future package split: `contract/` is the sole inter-domain shared face (`slots.ts` slot declarations + composed slot props including the tool-row contract, `views.ts` shared primitives, `tool-call-model.ts`); the `skeleton/`, `chat/`, and `toolviews/` (sample registrants) domain directories import contract files and never each other; `apply.ts` is the only assembly point allowed to import all three domains. The `/client` export surface is the contract only — `apply`/`inject`, the two service classes, and the `contract/` type families; implementation components (skeleton, chat rows) and the store factory stay internal and reach the page exclusively through apply's slot registrations (tests take them via the `./src/*` subpath).

--- a/packages/client/ui-conversation/README.zh.md
+++ b/packages/client/ui-conversation/README.zh.md
@@ -12,13 +12,13 @@

 工具行同样是 slot：独立工具环（`ToolViewRegistry`／`ctx.toolviews`／outlet）已经退役。聊天配置项声明键控的 `'conversation.chat.toolview'` 空位（Session scope；key 空间在运行时开放）；其渲染点逐行通过 `entryKey: toolName` 分发，并以 `GenericToolCard` 作为调用点 `fallback`。owner 载荷是统一的 `ToolRowOwnerProps`（`callId`／`toolName`／`block`／`openFile`），`ToolRowProps` 则预先将其与 Session 标准工具包组合。注册方只是普通插件：`ctx.slots.register({ name: 'conversation.chat.toolview', key: '<tool>', inject? }, Row)`，以 `inject: ['slots', 'conversation']` 作为加载顺序 seam（apply 在聊天注册后挂载 ConversationService，因此服务存在即可保证 slot 已声明）；Session 区分在组件内部完成（`useSessions` 读取 `parentId`，bash 示例是第三方姿态的范例）。Trajectory/waterfall 工具视图 slot 共享此形状，并随各自的渲染点落地（RendersCheck 会拒绝没有任何渲染方的声明）。

-todo 两个面就是在该形状上的两个注册项，都是普通注册方插件，`inject: ['slots', 'conversation']`。`TodoRow` 占用 `'conversation.chat.toolview'` 的 `todo_write` key，摘要该次调用「试图写入」的内容（从其 args 解析出 `<已完成>/<总数> 已完成 · <进行中条目>`；模型 JSON 残缺或形状不对时回落到通用摘要；非 ok 执行状态保留通用状态点，使被取消的调用绝不读成一次已完成的更新）。`TodoDock` 以 `order: -1` 占用 `'conversation.input.dock'` 列表 slot（位于队列行之上），是常驻的计划条：它从会话快照中选取 `todos` 并渲染 `TodoPanel`，后者接收纯列表，在列表为空时自我隐藏，折叠时收成标题加 `"<已完成>/<总数> tasks · <n> in progress"` 的表头（状态图标为 figma 的勾选／进行中／虚线未开始一组）。选取由 dock 适配器负责，因此面板保持为其 props 的纯函数；常驻列表放在此处而非行内，行才能保持单行。输入区 composer 链隐藏的一切（例如 ui-question 对 `conversation.composer` 的接管）也会隐藏整个 dock，包括这条计划条。
+todo 两个面就是在该形状上的两个注册项，都是普通注册方插件，`inject: ['slots', 'conversation']`。`TodoRow` 占用 `'conversation.chat.toolview'` 的 `todo_write` key，摘要该次调用「试图写入」的内容（从其 args 解析出 `<已完成>/<总数> 已完成 · <进行中条目>`；模型 JSON 残缺或形状不对时回落到通用摘要；非 ok 执行状态保留通用状态点，使被取消的调用绝不读成一次已完成的更新）。`TodoDock` 以 `order: -1` 占用 `'conversation.input.dock'` 列表 slot（位于队列行之上），是常驻的计划条：它通过 `useProjection` 读取由 Host 计算的 `todos` key 并渲染 `TodoPanel`，后者接收纯列表，在列表为空时自我隐藏，折叠时收成标题加 `"<已完成>/<总数> tasks · <n> in progress"` 的表头（状态图标为 figma 的勾选／进行中／虚线未开始一组）。选取由 dock 适配器负责，因此面板保持为其 props 的纯函数；常驻列表放在此处而非行内，行才能保持单行。输入区 composer 链隐藏的一切（例如 ui-question 对 `conversation.composer` 的接管）也会隐藏整个 dock，包括这条计划条。

 逐 Session UI 状态中的选择与活跃视图位于已声明的聊天 store（`stores.ts` `createChatStore`）中；InputHub 拥有输入区状态机，并将草稿镜像到该 store 以便持久化。apply 将同一个 store handle 传给严格限定于会话的子树、聊天视图和详情注册，因此每个会话内共享一个实例，框架拥有其生命周期。组件保持纯粹：框架标准工具包提供 `useSession`／`sessionId`、全局 `useSessions`／`useWorkspaces`，以及输入状态机的 `useInput`／`inputActions`；store 表层与 inject factory 提供其余状态和回调。

 输入栏为 `'conversation.input.plan'` 和 `'conversation.input.model'` 声明会话作用域的单实例 seat，并为 overlay、dock、left 和 right 输入扩展声明列表 slot。InputBar 将模型 seat 渲染在 pending 指示器与发送／停止按钮之前。各功能包拥有相应控件及其状态；ui-conversation 提供放置位置、`locked` owner prop 和标准 slot share。常驻无会话壳使用 `DisabledInputBar`，因此不会分发任何会话作用域的控件 seat。

-聊天统计行只从 `ConversationSnapshot.metrics` 读取持久的 token 计数／当前压力，以及运行时提供的连接本地容量覆盖值；可见节点仅提供既有的轮次和步骤计数。它以相互独立的紧凑值显示未缓存输入、输出与缓存读取，通过 `cacheRead / (uncachedInput + cacheRead)` 计算缓存命中率而不计入缓存写入，并且只有当前 mux 连接观察到带容量的模型请求后才显示上下文占用率。在该请求之前、重连／恢复／新订阅之后，或在请求不带容量之后，系统都会省略百分比，并把上下文标为「未知」，而不会提前查询或根据历史记录重建。
+聊天统计行从 `ConversationSnapshot.metrics` 读取持久的 token 计数／当前压力，并且只在展示时把它们与独立的连接本地 `modelRequestContextWindow` 结合；可见节点仅提供既有的轮次和步骤计数。它以相互独立的紧凑值显示未缓存输入、输出与缓存读取，通过 `cacheRead / (uncachedInput + cacheRead)` 计算缓存命中率而不计入缓存写入，并且只有当前 mux 连接观察到带容量的模型请求后才显示上下文占用率。在该请求之前、重连／恢复／新订阅之后，或在请求不带容量之后，系统都会省略百分比，并把上下文标为「未知」，而不会提前查询或根据历史记录重建。

 `src/client/` 按未来的包拆分组织：`contract/` 是唯一的跨领域共享表层（`slots.ts` slot 声明 + 组合后的 slot props，包括工具行契约、`views.ts` 共享原语、`tool-call-model.ts`）；`skeleton/`、`chat/` 和 `toolviews/`（示例注册方）领域目录只导入 contract 文件，彼此绝不导入；`apply.ts` 是唯一允许导入全部三个领域的组装点。`/client` 导出表层只包含契约：`apply`／`inject`、两个服务类和 `contract/` 类型家族；实现组件（骨架、聊天行）与 store factory 保持内部状态，只能通过 apply 的 slot 注册到达页面（测试通过 `./src/*` 子路径获取它们）。

--- a/packages/client/ui-conversation/package.json
+++ b/packages/client/ui-conversation/package.json
@@ -49,6 +49,8 @@
  },
  "devDependencies": {
    "@deepseek-ai/dsh-client-runtime": "workspace:^",
+    "@deepseek-ai/dsh-session-projection": "workspace:^",
+    "@deepseek-ai/dsh-tool-todo": "workspace:^",
    "@deepseek-ai/dsh-client-ui-layout": "workspace:^",
    "@deepseek-ai/dsh-client-ui-primitives": "workspace:^",
    "@deepseek-ai/dsh-client-ui-slash": "workspace:^",
--- a/packages/client/ui-conversation/src/client/apply.ts
+++ b/packages/client/ui-conversation/src/client/apply.ts
@@ -159,7 +159,10 @@ export function apply(ctx: Context): void {
    id: 'chat',
    order: 0,
    label: 'Chat',
-    children: { 'conversation.chat.toolview': { kind: 'keyed', scope: 'session' } },
+    children: {
+      'conversation.chat.toolview': { kind: 'keyed', scope: 'session' },
+      'conversation.chat.commandview': { kind: 'keyed', scope: 'session' },
+    },
    store: chatStore,
    inject: (sessionId: SessionId, actions: BoundActions<typeof chatStore>): ChatViewInjected => {
      const scoped = scopedConversation(sessions, sessionId)
--- a/packages/client/ui-conversation/src/client/chat/ChatView.tsx
+++ b/packages/client/ui-conversation/src/client/chat/ChatView.tsx
@@ -20,13 +20,14 @@ import {
  memo, useLayoutEffect, useMemo, useRef, useState, type ReactNode,
 } from 'react'
 import type {
-  CodeSubCall, ConversationNode, ConversationSnapshot, RunningToolCall, ToolResultNode,
+  CodeSubCall, CommandNode, ConversationNode, ConversationSnapshot, RunningToolCall, ToolResultNode,
 } from '@deepseek-ai/dsh-client-runtime/client'
 import type { SnapshotSelectorHook } from '@deepseek-ai/dsh-client-ui-slots'
 import { IconChevronDownOutline14 } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ChatViewSlotProps } from '../contract/slots.ts'
 import { deriveChatFlow, type ChatFlowItem } from './chat-flow.ts'
 import { AssistantMarkdown } from './AssistantMarkdown.tsx'
+import { GenericCommandCard } from './GenericCommandCard.tsx'
 import { GenericToolCard } from './GenericToolCard.tsx'
 import { MessageItem } from './MessageItem.tsx'
 import { PendingCard } from './PendingCard.tsx'
@@ -151,6 +152,24 @@ const ToolGroup = memo(function ToolGroup({ renderSlot, results, openFile, selec
  )
 })

+/** One command lifecycle row: keyed dispatch on the command name with the
+ *  generic card as the render-site fallback (zero registration required). A
+ *  run-less cross-window node has no name and always lands on the fallback. */
+const CommandRow = memo(function CommandRow({ renderSlot, node }: {
+  renderSlot: RenderToolRow
+  node: CommandNode
+}) {
+  const owner = useMemo(() => ({ node }), [node])
+  return (
+    <div className={css.callRow}>
+      {renderSlot('conversation.chat.commandview', owner, {
+        entryKey: node.name ?? '',
+        fallback: <GenericCommandCard {...owner} />,
+      })}
+    </div>
+  )
+})
+
 /** Turn loader: one row of four 2.5px pixels (half a notch above the StateDot
 *  2px cell, same blue) chasing left to right with a stepped trail — flat
 *  keyframe holds, no tweening, no rotation. Phase offsets come from
@@ -315,6 +334,9 @@ export function ChatView({ useSession, useSessions, useStore, renderSlot, sessio
    if (node.kind === 'assistant') {
      return <AssistantMarkdown key={item.key} blocks={node.blocks} streaming={false} interrupted={node.interrupted} />
    }
+    if (node.kind === 'command') {
+      return <CommandRow key={item.key} renderSlot={renderSlot} node={node} />
+    }
    /* v8 ignore next -- tool-result never reaches here: deriveChatFlow folds them into groups. */
    if (node.kind === 'tool-result') return null
    return <MessageItem key={item.key} node={node} />
--- a/packages/client/ui-conversation/src/client/chat/GenericCommandCard.tsx
+++ b/packages/client/ui-conversation/src/client/chat/GenericCommandCard.tsx
@@ -0,0 +1,38 @@
+// GenericCommandCard: the default command row — a stripped-down
+// GenericToolCard rendering the dispatched command line and the settlement
+// text. Supplied by the chat view as the keyed commandview slot's render-site
+// fallback (an unregistered command name lands here); registrants may compose
+// it as a base, feeding the same owner payload through.
+
+import { ToolRow } from './ToolRow.tsx'
+import type { ToolRowState } from '../contract/tool-call-model.ts'
+import type { CommandRowOwnerProps } from '../contract/slots.ts'
+import { IconApiOutline14 } from '@deepseek-ai/dsh-client-ui-primitives'
+
+/** Node state → row state semantic (running while unsettled; outcome kind after). */
+function stateOf(outcome: CommandRowOwnerProps['node']['outcome']): ToolRowState {
+  if (outcome === null) return 'running'
+  return outcome.kind === 'error' ? 'error' : 'ok'
+}
+
+export function GenericCommandCard({ node }: CommandRowOwnerProps) {
+  const text = node.outcome?.text
+  const summary = node.outcome === null
+    ? '执行中…'
+    : text ?? (node.outcome.kind === 'error' ? '命令失败' : '已完成')
+  // Display line rebuilt from the structured payload (args carries its own
+  // separator whitespace verbatim); a cross-window node whose run page fell
+  // out of the window has neither.
+  const title = node.name === null ? '命令' : `/${node.name}${node.args ?? ''}`
+  return (
+    <ToolRow
+      variant="others"
+      icon={<IconApiOutline14 size={16} />}
+      title={title}
+      summary={summary}
+      // Expandable only when the outcome text overflows a one-line summary.
+      body={text !== undefined && text.includes('\n') ? text : null}
+      state={stateOf(node.outcome)}
+    />
+  )
+}
--- a/packages/client/ui-conversation/src/client/chat/StatsLine.tsx
+++ b/packages/client/ui-conversation/src/client/chat/StatsLine.tsx
@@ -56,12 +56,13 @@ export function cacheHitPercent(metrics: SessionMetrics): number | null {

 /**
 * Current context occupancy using the TUI's integer rounding and upper clamp.
- * @param metrics - Host-owned pressure plus current-connection request capacity.
+ * @param metrics - Host-owned durable pressure.
+ * @param contextWindow - capacity from the latest request observed on this mux generation.
 * @returns occupancy percent, or null when either input is unavailable.
 */
-export function contextPercent(metrics: SessionMetrics): number | null {
-  if (metrics.contextTokens === undefined || metrics.contextWindow === undefined) return null
-  return Math.min(100, Math.round(metrics.contextTokens / metrics.contextWindow * 100))
+export function contextPercent(metrics: SessionMetrics, contextWindow: number | undefined): number | null {
+  if (metrics.contextTokens === undefined || contextWindow === undefined) return null
+  return Math.min(100, Math.round(metrics.contextTokens / contextWindow * 100))
 }

 /** Props: the conversation-snapshot selector hook (handed down by ChatView). */
@@ -70,6 +71,7 @@ export interface StatsLineProps { useSession: SnapshotSelectorHook<ConversationS
 export const StatsLine = memo(function StatsLine({ useSession }: StatsLineProps) {
  const nodes = useSession(s => s.nodes)
  const metrics = useSession(s => s.metrics)
+  const contextWindow = useSession(s => s.modelRequestContextWindow)
  const counts = useMemo(() => deriveVisibleCounts(nodes), [nodes])
  if (counts.steps === 0 && (
    metrics === null
@@ -90,10 +92,10 @@ export const StatsLine = memo(function StatsLine({ useSession }: StatsLineProps)
    parts.push(`${formatMetricTokens(metrics.cacheReadTokens)} cache read`)
    const cacheHit = cacheHitPercent(metrics)
    if (cacheHit !== null) parts.push(`cache hit ${cacheHit}%`)
-    const context = contextPercent(metrics)
+    const context = contextPercent(metrics, contextWindow)
    parts.push(context === null
      ? 'context unknown'
-      : `context ${context}% of ${formatMetricTokens(metrics.contextWindow as number)}`)
+      : `context ${context}% of ${formatMetricTokens(contextWindow as number)}`)
  }
  parts.push(`${counts.turns} turns`)
  parts.push(`${counts.steps} steps`)
--- a/packages/client/ui-conversation/src/client/contract/slots.ts
+++ b/packages/client/ui-conversation/src/client/contract/slots.ts
@@ -3,7 +3,7 @@ import type { ReactNode, RefObject } from 'react'
 import type {
  InjectFace, MaybeSnapshotSelectorHook, PropsRenderSlots, PropsRuntime, PropsStore, SnapshotSelectorHook,
 } from '@deepseek-ai/dsh-client-ui-slots'
-import type { ConversationSnapshot, ObservableSnapshot, PendingInteraction, SessionId, ToolCallBlock, WorkspaceId } from '@deepseek-ai/dsh-client-runtime/client'
+import type { CommandNode, ConversationSnapshot, ObservableSnapshot, PendingInteraction, SessionId, ToolCallBlock, WorkspaceId } from '@deepseek-ai/dsh-client-runtime/client'
 import type {} from '@deepseek-ai/dsh-client-ui-layout/client'
 import type { ComposerKeyboard, InputActions, InputNotice, InputState } from '../input/contract.ts'
 import type { createChatStore } from '../stores.ts'
@@ -33,6 +33,15 @@ declare module '@deepseek-ai/dsh-client-ui-slots' {
     * `fallback` for unregistered tools.
     */
    'conversation.chat.toolview': { kind: 'keyed'; scope: 'session'; owner: ToolRowOwnerProps }
+    /**
+     * The chat view's per-command row hole: keyed dispatch on the command
+     * name (`command/run.name`; a run-less cross-window node has none and
+     * always lands on the fallback). Declared by the chat view entry; the
+     * render site dispatches via `entryKey: name` with GenericCommandCard as
+     * the `fallback` — a slash command renders durably with zero
+     * registration, and a domain upgrades by registering one row component.
+     */
+    'conversation.chat.commandview': { kind: 'keyed'; scope: 'session'; owner: CommandRowOwnerProps }
    /**
     * The composer takeover chain: entries are selector-routed replacements
     * of the default InputBar. Declared by this package's 'conversation'
@@ -161,6 +170,22 @@ export interface ToolRowOwnerProps {
 */
 export type ToolRowProps = PropsRuntime<'conversation.chat.toolview'>

+/**
+ * Owner share of the per-command row slot: the frozen {@link CommandNode}
+ * slice off the snapshot (cache-stable reference — memo premise). The node
+ * carries the whole lifecycle (structured name/args, pairing id,
+ * outcome-or-executing), so a
+ * registrant needs no second data channel; domain state arrives through its
+ * own projection cell.
+ */
+export interface CommandRowOwnerProps {
+  /** Folded command lifecycle node (run + optional done). */
+  node: CommandNode
+}
+
+/** Full props of a registered command-row component (same shape rule as {@link ToolRowProps}). */
+export type CommandRowProps = PropsRuntime<'conversation.chat.commandview'>
+
 /**
 * Base props of a conversation view entry: the framework standard kit for the
 * session-scope 'conversation.view' slot (useSession narrowed to the
@@ -296,9 +321,9 @@ export interface ChatViewInjected {
  loadOlder: () => void
 }

-/** Full chat-view component props: runtime share & the declared toolview hole's render share & store share & injected share. */
+/** Full chat-view component props: runtime share & the declared toolview/commandview holes' render share & store share & injected share. */
 export type ChatViewSlotProps =
-  PropsRuntime<'conversation.view'> & PropsRenderSlots<'conversation.chat.toolview'>
+  PropsRuntime<'conversation.view'> & PropsRenderSlots<'conversation.chat.toolview' | 'conversation.chat.commandview'>
  & PropsStore<ChatStore> & ChatViewInjected

 /**
--- a/packages/client/ui-conversation/src/client/index.ts
+++ b/packages/client/ui-conversation/src/client/index.ts
@@ -13,7 +13,8 @@ export type {
 } from './contract/views.ts'
 export type { ToolCallBlock } from './contract/tool-call-model.ts'
 export type {
-  ChatStore, ChatViewInjected, ChatViewSlotProps, ComposerBarInjected, ComposerChainProps, ConversationInjected,
+  ChatStore, ChatViewInjected, ChatViewSlotProps, CommandRowOwnerProps, CommandRowProps, ComposerBarInjected,
+  ComposerChainProps, ConversationInjected,
  ConversationSessionInjected, ConversationSlotProps, ConvViewOwnerProps, ConvViewProps, DetailsInjected, DetailsSlotProps,
  EmptyWorkspaceOwnerProps, ToolRowOwnerProps, ToolRowProps,
 } from './contract/slots.ts'
--- a/packages/client/ui-conversation/src/client/skeleton/InputBar.module.css
+++ b/packages/client/ui-conversation/src/client/skeleton/InputBar.module.css
@@ -87,6 +87,13 @@
  box-shadow: var(--dsw-shadow-lv2);
  font-size: 16px;
  line-height: 24px;
+  /* Elevated surface in dark, same as the menus: the textarea inside scrolls
+     once the composer hits its height cap, so the thumb takes the l2 pair.
+     Declared on the card because the elevation belongs to the surface, and the
+     custom properties inherit down to the textarea that actually scrolls (see
+     ui-theme styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
 }

 .accessory {
--- a/packages/client/ui-conversation/src/client/skeleton/TodoPanel.module.css
+++ b/packages/client/ui-conversation/src/client/skeleton/TodoPanel.module.css
@@ -11,6 +11,13 @@
  border: 1px solid var(--dsw-alias-border-l1);
  border-radius: 14px;
  background: var(--dsw-specific-tip);
+  /* Elevated surface: `--dsw-specific-tip` is the same dark rung as the menu
+     surface, and `.list` scrolls inside this card, so the thumb takes the l2
+     elevation tokens. Declared here because the elevation belongs to the
+     surface, and the custom properties inherit down to `.list` (see ui-theme
+     styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
 }

 .body {
--- a/packages/client/ui-conversation/src/client/skeleton/TodoPanel.tsx
+++ b/packages/client/ui-conversation/src/client/skeleton/TodoPanel.tsx
@@ -8,7 +8,11 @@
 import { useId, useState } from 'react'
 import type { Context } from 'cordis'
 import type { PropsRuntime } from '@deepseek-ai/dsh-client-ui-slots'
-import type { TodoItem } from '@deepseek-ai/dsh-client-runtime/client'
+// The domain's client-namespace pure-type outlet: one import edge delivers
+// the `todos` projection-key merge (single source, no consumer-side restated
+// declare) and the payload type. Type-only by construction — the outlet is
+// free of host value imports, so no host Context merge enters this program.
+import type { TodoItem } from '@deepseek-ai/dsh-tool-todo/client'
 import { IconChevronDownOutline14, IconChevronUpOutline14 } from '@deepseek-ai/dsh-client-ui-primitives'
 import css from './TodoPanel.module.css'

@@ -115,10 +119,10 @@ export function TodoPanel({ todos }: TodoPanelProps) {
 /** Full props of a dock entry: InputZone owner share + session standard kit + global seat. */
 export type TodoDockProps = PropsRuntime<'conversation.input.dock'>

-/** Dock adapter: selects the plan off the session snapshot and hands the strip a plain list. */
-export function TodoDock({ useSession }: TodoDockProps) {
-  const todos = useSession(s => s.todos)
-  return <TodoPanel todos={todos} />
+/** Dock adapter: reads the host-computed 'todos' projection (whole list; absent or null renders nothing). */
+export function TodoDock({ useProjection }: TodoDockProps) {
+  const todos = useProjection('todos')
+  return <TodoPanel todos={todos ?? []} />
 }

 /**
--- a/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-code-subcalls.spec.tsx
@@ -56,7 +56,7 @@ function snapshotWith(
 ): ConversationSnapshot {
  return {
    sessionId: SID, nodes, foldDegraded: false, partial: null, runningCalls, codeDispatches,
-    pending: [], queue: [], todos: [], running: runningCalls.length > 0, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: runningCalls.length > 0, composerPhase: 'active', removed: false,
    openState: 'open', openError: null,
    hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null, metrics: null,
  }
--- a/packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx
@@ -30,7 +30,7 @@ const assistant = (seq: number, turn: number, usage?: unknown): AssistantMessage
 function snapshotBase(): ConversationSnapshot {
  return {
    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
    hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null, metrics: null,
  }
 }
@@ -82,13 +82,11 @@ describe('stats derivation', () => {
      cacheReadTokens: 900,
      cacheWriteTokens: 50_000,
      contextTokens: 34_500,
-      contextWindow: 100_000,
    }
    expect(cacheHitPercent(durable)).toBe(90)
-    expect(contextPercent(durable)).toBe(35)
-    expect(contextPercent({ ...durable, contextTokens: 200_000 })).toBe(100)
-    const { contextWindow: _contextWindow, ...withoutContextWindow } = durable
-    expect(contextPercent(withoutContextWindow)).toBeNull()
+    expect(contextPercent(durable, 100_000)).toBe(35)
+    expect(contextPercent({ ...durable, contextTokens: 200_000 }, 100_000)).toBe(100)
+    expect(contextPercent(durable, undefined)).toBeNull()
    expect(cacheHitPercent({ ...durable, uncachedInputTokens: 0, cacheReadTokens: 0 })).toBeNull()
  })

@@ -115,8 +113,8 @@ describe('StatsLine', () => {
        cacheReadTokens: 2_172_544,
        cacheWriteTokens: 99_999,
        contextTokens: 89_600,
-        contextWindow: 256_000,
      },
+      modelRequestContextWindow: 256_000,
    })
    const view = render(<StatsLine {...props(source)} />)
    expect(view.getByText(
--- a/packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-toolview-slot.spec.tsx
@@ -43,7 +43,7 @@ const toolResult = (seq: number, callId: string, name: string, args = '{"command
 function snapshotWith(nodes: ToolResultNode[]): ConversationSnapshot {
  return {
    sessionId: SID, nodes, foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
    hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null, metrics: null,
  }
 }
--- a/packages/client/ui-conversation/tests/chat-view.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-view.spec.tsx
@@ -7,7 +7,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { Profiler } from 'react'
 import { act, cleanup, fireEvent, render } from '@testing-library/react'
 import type {
-  AssistantMessageNode, ConversationNode, ConversationSnapshot, RunningToolCall, SessionId,
+  AssistantMessageNode, CommandNode, ConversationNode, ConversationSnapshot, RunningToolCall, SessionId,
  SessionListState, ToolResultNode, UserMessageNode, WorkspaceListState,
 } from '@deepseek-ai/dsh-client-runtime/client'
 import { bindSnapshotSelector } from '@deepseek-ai/dsh-client-web-react'
@@ -30,7 +30,7 @@ const SID = 's1' as SessionId
 function snapshotBase(): ConversationSnapshot {
  return {
    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
    hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null, metrics: null,
  }
 }
@@ -106,6 +106,7 @@ function makeHarness(init?: Partial<ConversationSnapshot>) {
    useSession: bindSnapshotSelector(source),
    useSessions: emptySessions(),
    useWorkspaces: emptyWorkspaces(),
+    useProjection: (() => undefined),
    useInput: (() => { throw new Error('unused') }),
    inputActions: { setDraft: () => {}, submit: () => {} },
    useStore: bindSnapshotSelector(chat),
@@ -395,4 +396,41 @@ describe('ChatView', () => {
    const view = render(<h.ChatView {...h.props} />)
    expect(view.getByText(/等待审批/)).toBeTruthy()
  })
+
+  it('renders command nodes as durable rows: settled text, error state, executing spinner, run-less soft-fall', () => {
+    const command = (over: Partial<CommandNode>): CommandNode => ({
+      kind: 'command', seq: 5, time: 5_000, commandId: 'cmd-1' as CommandNode['commandId'],
+      name: 'plan', args: '', outcome: { kind: 'success', text: '已进入 plan mode' },
+      ...over,
+    })
+    // Settled success: the command line is the title, the outcome text the summary.
+    const settled = makeHarness({ nodes: [user(1, 'hi'), command({})] })
+    const view = render(<settled.ChatView {...settled.props} />)
+    expect(view.getByText('/plan')).toBeTruthy()
+    expect(view.getByText('已进入 plan mode')).toBeTruthy()
+
+    // Error outcome flips the row state; a text-less error gets the default copy.
+    const failed = makeHarness({
+      nodes: [command({ seq: 6, commandId: 'cmd-2' as CommandNode['commandId'], outcome: { kind: 'error' } })],
+    })
+    const fv = render(<failed.ChatView {...failed.props} />)
+    expect(fv.container.querySelector('[data-state="error"]')).not.toBeNull()
+    expect(fv.getByText('命令失败')).toBeTruthy()
+
+    // Still executing: running state with the executing copy.
+    const executing = makeHarness({
+      nodes: [command({ seq: 7, commandId: 'cmd-3' as CommandNode['commandId'], outcome: null })],
+    })
+    const xv = render(<executing.ChatView {...executing.props} />)
+    expect(xv.container.querySelector('[data-state="running"]')).not.toBeNull()
+    expect(xv.getByText('执行中…')).toBeTruthy()
+
+    // Cross-window soft-fall (run page truncated): generic title, outcome preserved.
+    const orphan = makeHarness({
+      nodes: [command({ seq: 8, commandId: 'cmd-4' as CommandNode['commandId'], name: null, args: null, outcome: { kind: 'success' } })],
+    })
+    const ov = render(<orphan.ChatView {...orphan.props} />)
+    expect(ov.getByText('命令')).toBeTruthy()
+    expect(ov.getByText('已完成')).toBeTruthy()
+  })
 })
--- a/packages/client/ui-conversation/tests/gate-branch-tails.spec.tsx
+++ b/packages/client/ui-conversation/tests/gate-branch-tails.spec.tsx
@@ -19,7 +19,7 @@ const SID = 's1' as SessionId
 function snapshotBase(): ConversationSnapshot {
  return {
    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false, openState: 'open', openError: null,
    hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null, metrics: null,
  }
 }
@@ -86,6 +86,7 @@ describe('render branch tails', () => {
        useSession={bindSnapshotSelector({ getSnapshot: () => snap, subscribe: () => () => {} })}
        useSessions={bindSnapshotSelector(emptyList)}
        useWorkspaces={bindSnapshotSelector(emptyWorkspaces)}
+        useProjection={(() => undefined)}
        useInput={(() => { throw new Error('unused') })}
        inputActions={{ setDraft: () => {}, submit: () => {} }}
        useStore={bindSnapshotSelector(chat)}
@@ -121,6 +122,7 @@ describe('render branch tails', () => {
        useSession={bindSnapshotSelector({ getSnapshot: () => snap, subscribe: () => () => {} })}
        useSessions={bindSnapshotSelector(emptyList)}
        useWorkspaces={bindSnapshotSelector(emptyWorkspaces)}
+        useProjection={(() => undefined)}
        useInput={(() => { throw new Error('unused') })}
        inputActions={{ setDraft: () => {}, submit: () => {} }}
        useStore={bindSnapshotSelector(chat)}
--- a/packages/client/ui-conversation/tests/input-bar.spec.tsx
+++ b/packages/client/ui-conversation/tests/input-bar.spec.tsx
@@ -21,7 +21,7 @@ const SID = 's1' as SessionId
 function snapshotOf(overrides: Partial<ConversationSnapshot> = {}): ConversationSnapshot {
  return {
    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
    openState: 'open', openError: null, hasMore: false, loadingOlder: false,
    promptError: null, blank: false, lastAgentError: null, metrics: null,
    ...overrides,
@@ -88,6 +88,7 @@ function bench(over?: BenchOptions) {
      items: [], state: 'idle', phase: 'ready', error: null,
      baselinesReady: true, recentWorkspaceId: undefined,
    })),
+    useProjection: (() => undefined),
    useInput: bindSnapshotSelector(shell.state),
    inputActions: shell.actions,
    keyboard: shell,
--- a/packages/client/ui-conversation/tests/input-matrix.spec.tsx
+++ b/packages/client/ui-conversation/tests/input-matrix.spec.tsx
@@ -24,7 +24,7 @@ const SID = 's1' as SessionId
 function mountBar(shell: SessionInputShell, over?: { running?: boolean; disabled?: boolean }) {
  const session = createSnapshotStore<ConversationSnapshot>({
    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: over?.running ?? false, composerPhase: 'active',
+    pending: [], queue: [], running: over?.running ?? false, composerPhase: 'active',
    removed: over?.disabled ?? false, openState: 'open', openError: null, hasMore: false,
    loadingOlder: false, promptError: null, blank: false, lastAgentError: null, metrics: null,
  })
@@ -39,6 +39,7 @@ function mountBar(shell: SessionInputShell, over?: { running?: boolean; disabled
      items: [], state: 'idle', phase: 'ready', error: null,
      baselinesReady: true, recentWorkspaceId: undefined,
    })),
+    useProjection: (() => undefined),
    useInput: bindSnapshotSelector(shell.state),
    inputActions: shell.actions,
    keyboard: shell,
--- a/packages/client/ui-conversation/tests/input-scenarios.spec.tsx
+++ b/packages/client/ui-conversation/tests/input-scenarios.spec.tsx
@@ -110,7 +110,7 @@ async function scopedBench(register?: (slash: SlashService) => void) {
  const wiring = shell
  const sessionStore = createSnapshotStore<ConversationSnapshot>({
    sessionId, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
    openState: 'open', openError: null, hasMore: false, loadingOlder: false,
    promptError: null, blank: false, lastAgentError: null, metrics: null,
  })
@@ -125,6 +125,7 @@ async function scopedBench(register?: (slash: SlashService) => void) {
      items: [], state: 'idle', phase: 'ready', error: null,
      baselinesReady: true, recentWorkspaceId: undefined,
    })),
+    useProjection: (() => undefined),
    useInput: bindSnapshotSelector(shell.state),
    inputActions: shell.actions,
    keyboard: shell,
--- a/packages/client/ui-conversation/tests/queue-dock.spec.tsx
+++ b/packages/client/ui-conversation/tests/queue-dock.spec.tsx
@@ -19,7 +19,7 @@ const SID = 's1' as SessionId
 function snapshotWith(queue: QueuedMessage[]): ConversationSnapshot {
  return {
    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue, todos: [], running: true, composerPhase: 'active', removed: false, openState: 'open', openError: null,
+    pending: [], queue, running: true, composerPhase: 'active', removed: false, openState: 'open', openError: null,
    hasMore: false, loadingOlder: false, promptError: null, blank: false, lastAgentError: null, metrics: null,
  }
 }
@@ -53,6 +53,7 @@ function kitFor(snapshot: ConversationSnapshot) {
    sessionId: SID,
    useSessions: (() => { throw new Error('unused') }) as unknown as SnapshotSelectorHook<SessionListState>,
    useWorkspaces: (() => { throw new Error('unused') }) as never,
+    useProjection: (() => undefined) as never,
    useInput: (() => { throw new Error('unused') }) as never,
    inputActions: { setDraft: () => {}, submit: () => {} } as never,
    session: snapshot,
--- a/packages/client/ui-conversation/tests/skeleton.spec.tsx
+++ b/packages/client/ui-conversation/tests/skeleton.spec.tsx
@@ -48,7 +48,7 @@ const workspaceState = (items: readonly WorkspaceView[]): WorkspaceListState =>
 function conversationSnapshot(overrides: Partial<ConversationSnapshot> = {}): ConversationSnapshot {
  return {
    sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [], codeDispatches: new Map(),
-    pending: [], queue: [], todos: [], running: false, composerPhase: 'active', removed: false,
+    pending: [], queue: [], running: false, composerPhase: 'active', removed: false,
    openState: 'open', openError: null, hasMore: false, loadingOlder: false,
    promptError: null, blank: false, lastAgentError: null, metrics: null,
    ...overrides,
@@ -93,6 +93,7 @@ function mount(
          useSession={useSession}
          useSessions={props.useSessions}
          useWorkspaces={props.useWorkspaces}
+          useProjection={(() => undefined)}
          useInput={useInput}
          inputActions={inputActions}
          useStore={bindSnapshotSelector(chat)}
@@ -115,6 +116,7 @@ function mount(
          useSession={useSession}
          useSessions={props.useSessions}
          useWorkspaces={props.useWorkspaces}
+          useProjection={(() => undefined)}
          useInput={useInput}
          inputActions={inputActions}
          keyboard={wiring}
@@ -135,6 +137,7 @@ function mount(
    useSession,
    useSessions: bindSnapshotSelector(sessions),
    useWorkspaces: bindSnapshotSelector(workspaces),
+    useProjection: (() => undefined),
    useInput,
    inputActions,
    renderSlot,
--- a/packages/client/ui-conversation/tests/todo-panel.spec.tsx
+++ b/packages/client/ui-conversation/tests/todo-panel.spec.tsx
@@ -10,8 +10,9 @@ import { act, cleanup, fireEvent, render, screen } from '@testing-library/react'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import { bindSnapshotSelector } from '@deepseek-ai/dsh-client-web-react'
 import { createSnapshotStore } from '@deepseek-ai/dsh-client-runtime/client'
-import type { TodoItem, ToolResultNode } from '@deepseek-ai/dsh-client-runtime/client'
+import type { ToolResultNode } from '@deepseek-ai/dsh-client-runtime/client'
 import type { ToolRowProps } from '@deepseek-ai/dsh-client-ui-conversation/client'
+import type { TodoItem } from '@deepseek-ai/dsh-tool-todo/client'
 // Export discipline: packages/client/AGENTS.md.
 import { TodoRow, todoToolview } from '../src/client/toolviews/todo-row.tsx'
 import type { TodoDockProps } from '../src/client/skeleton/TodoPanel.tsx'
@@ -64,20 +65,23 @@ describe('TodoPanel', () => {
  })
 })

-/** Dock props stub: the adapter reads useSession only; the rest of the owner share is unused. */
-function dockProps(store: ReturnType<typeof createSnapshotStore<{ todos: readonly TodoItem[] }>>): TodoDockProps {
-  return { useSession: bindSnapshotSelector(store) } as unknown as TodoDockProps
+/** Dock props stub: the adapter reads the 'todos' projection only; the rest of the owner share is unused. */
+function dockProps(store: ReturnType<typeof createSnapshotStore<{ value: readonly TodoItem[] | null | undefined }>>): TodoDockProps {
+  const useProjection = (_key: string, selector?: (v: unknown) => unknown) =>
+    bindSnapshotSelector(store)(s => (selector ?? (v => v))(s.value))
+  return { useProjection } as unknown as TodoDockProps
 }

 describe('TodoDock', () => {
-  it('selects the plan off the session snapshot and follows later writes', () => {
-    const store = createSnapshotStore<{ todos: readonly TodoItem[] }>({ todos: [] })
+  it('reads the host-computed todos projection and follows pushed updates', () => {
+    const store = createSnapshotStore<{ value: readonly TodoItem[] | null | undefined }>({ value: undefined })
    render(<TodoDock {...dockProps(store)} />)
+    // Capability absent (no baseline/frame yet) renders nothing.
    expect(screen.queryByTestId('todo-panel')).toBeNull()
-    act(() => { store.set({ todos: LIST }) })
+    act(() => { store.set({ value: LIST }) })
    expect(screen.getByText('1/3 tasks · 1 in progress')).toBeTruthy()
-    // A rollback to the empty list retires the strip (the panel owns no data).
-    act(() => { store.set({ todos: [] }) })
+    // The pre-first-write whole value (null) retires the strip (the panel owns no data).
+    act(() => { store.set({ value: null }) })
    expect(screen.queryByTestId('todo-panel')).toBeNull()
  })

--- a/packages/client/ui-conversation/tsconfig.json
+++ b/packages/client/ui-conversation/tsconfig.json
@@ -23,6 +23,12 @@
    {
      "path": "../runtime"
    },
+    {
+      "path": "../../session-projection/session-projection"
+    },
+    {
+      "path": "../../todo/tool-todo"
+    },
    {
      "path": "../ui-slash"
    },
--- a/packages/client/ui-model/src/client/ModelSelect.module.css
+++ b/packages/client/ui-model/src/client/ModelSelect.module.css
@@ -79,6 +79,13 @@
  background: var(--dsw-specific-menu);
  box-shadow: var(--dsw-shadow-lv3);
  color: var(--dsw-alias-label-primary);
+  /* Elevated surface: the scrollbar thumb takes the l2 elevation tokens.
+     Declared here rather than on the scrolling `.groups` child so the
+     elevation choice sits with the surface; the custom properties inherit
+     down to whichever descendant actually scrolls (see ui-theme
+     styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
 }

 .status,
--- a/packages/client/ui-primitives/src/Menu.module.css
+++ b/packages/client/ui-primitives/src/Menu.module.css
@@ -17,6 +17,13 @@
  border-radius: 12px;
  background: var(--dsw-specific-menu);
  box-shadow: var(--dsw-shadow-lv3);
+  /* Elevated surface: the scrollbar thumb takes the l2 elevation tokens. The
+     declaration sits on the card rather than on `.scrollable .viewport`
+     because the elevation is a property of this surface, and the custom
+     properties inherit down to whichever descendant actually scrolls (see
+     ui-theme styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
 }

 /* Primary card is 218 wide in the design across both hosts. */
--- a/packages/client/ui-question/src/client/QuestionComposer.module.css
+++ b/packages/client/ui-question/src/client/QuestionComposer.module.css
@@ -19,6 +19,13 @@
  background: var(--dsw-specific-input-major);
  box-shadow: var(--dsw-shadow-lv1-blur);
  color: var(--dsw-alias-label-primary);
+  /* Elevated surface in dark, same as the menus: the option list inside scrolls
+     once the card hits the cap above, so the thumb takes the l2 pair. Declared
+     on the card because the elevation belongs to the surface, and the custom
+     properties inherit down to `.options` (see ui-theme styles/scrollbar.css
+     for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
 }

 .card,
--- a/packages/client/ui-question/tests/question-composer.spec.tsx
+++ b/packages/client/ui-question/tests/question-composer.spec.tsx
@@ -25,6 +25,7 @@ const kit = {
  useSession: (() => { throw new Error('unused') }) as unknown as SnapshotSelectorHook<ConversationSnapshot>,
  useSessions: (() => { throw new Error('unused') }) as unknown as SnapshotSelectorHook<SessionListState>,
  useWorkspaces: (() => { throw new Error('unused') }) as unknown as SnapshotSelectorHook<WorkspaceListState>,
+  useProjection: (() => undefined) as never,
  useInput: (() => { throw new Error('unused') }) as never,
  inputActions: { setDraft: () => { throw new Error('unused') }, submit: () => { throw new Error('unused') } } as never,
 }
--- a/packages/client/ui-settings/src/client/SettingsRoot.module.css
+++ b/packages/client/ui-settings/src/client/SettingsRoot.module.css
@@ -76,6 +76,13 @@
  overflow: hidden;
  background: var(--dsw-alias-bg-layer-2);
  box-shadow: var(--dsw-shadow-lv3);
+  /* Elevated surface: the scrollbar thumb takes the l2 elevation tokens.
+     Declared on the panel rather than the scrolling `.options` child so the
+     elevation choice sits with the surface; the custom properties inherit
+     down to whichever descendant scrolls (see ui-theme
+     styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
 }

 /* Nav rail (figma .Setting-nav 501:29958): 188 wide, pad (12,22,12,0),
--- a/packages/client/ui-slash/src/client/MenuView.module.css
+++ b/packages/client/ui-slash/src/client/MenuView.module.css
@@ -13,6 +13,10 @@
  max-width: 537px;
  max-height: 320px;
  overflow-y: auto;
+  /* Elevated surface: the scrollbar thumb takes the l2 elevation tokens
+     (see ui-theme styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
  padding: 4px;
  display: flex;
  flex-direction: column;
--- a/packages/client/ui-slots/src/renderer.ts
+++ b/packages/client/ui-slots/src/renderer.ts
@@ -44,6 +44,15 @@ export interface SessionMaybeProvideInfo {
  hooks: Record<string, HostObservable<unknown> | undefined>
  /** Static plain-member roster; values are undefined with the session. */
  props: Record<string, unknown>
+  /**
+   * Key-addressed projection value sources (the useProjection framework seat,
+   * session-projection RFC). Unlike `hooks`, the key space is open — values
+   * arrive from host-computed push frames — so the render side binds per
+   * resolved key instead of per static roster member. Faces are always
+   * defined per key (absence is an `undefined` snapshot); the whole member is
+   * absent with the session.
+   */
+  projections?: { faceOf(key: string): HostObservable<unknown> } | undefined
 }

 /** Definite per-session standard props resolved for strict session slots. */
--- a/packages/client/ui-theme/README.i18n.yaml
+++ b/packages/client/ui-theme/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-theme/README.md
-README.md: 1227df357cb93241fcf28da9b74d7ba15207e9c5
-README.zh.md: cd87ede7264c8d47dd780acaa11128e83d7862f9
+README.md: a1ff7d840dae86f5da98de1208ecda3b8b62026b
+README.zh.md: 49b52bcb1e07527e98c602086404228c5513091a
--- a/packages/client/ui-theme/README.md
+++ b/packages/client/ui-theme/README.md
@@ -4,6 +4,12 @@ English | [中文](README.zh.md)

 Theme plugin: ThemeService over the --dsw-* token base stylesheets (static scale + alias semantic layers). The service owns the theme preference (`light`/`dark`/`system`, persisted under `dsh.theme`), resolves `system` through `prefers-color-scheme`, and publishes immutable `ThemeSnapshot`s on the `theme/change` event; it never touches the DOM — ui-layout's presenter applies the resolved snapshot (`html { color-scheme }`, `body[data-ds-dark-theme]`, and inline alias tokens). Contract: api-contracts v3 §8.

+`src/styles/` holds five sheets, all imported by the web shell's `base.css`: `base.css`, `design-platform.css`, `scrollbar.css`, `gradient-shadow-text.css`, and `shiki.css`. `scrollbar.css` is the sole consumer of the `--dsw-alias-scrollbar-*` tokens and must follow `design-platform.css`, which declares them.
+
+Scrollbar rebinding contract: `scrollbar.css` binds `--dsh-scrollbar-thumb` and `--dsh-scrollbar-thumb-hover` on `body` to the l1 (base-surface) tokens, and both rendering paths read that pair. An elevated surface (menu, popover, dialog) sets `--dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2)` and `--dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2)` on its own container; one rebind retints whichever path the engine took.
+
+The two paths are mutually exclusive by construction. `scrollbar-width`/`scrollbar-color` sit inside `@supports not selector(::-webkit-scrollbar)` because a non-`auto` value of either makes Chromium and Safari discard every `::-webkit-scrollbar*` rule for that element, `::-webkit-scrollbar-thumb:hover` included — declaring both unconditionally leaves `--dsh-scrollbar-thumb-hover` with no rendering anywhere. Firefox therefore takes the standard properties and WebKit-based engines take the pseudo-elements, so the hover token only ever renders through the pseudo-element path. Reasoning and the measured computed values: [the scrollbar Agent Note](../../../.agents/notes/implemented/bug-fix/2026-07-28-themed-scrollbars-and-reserved-gutter.md).
+
 ## Model Experience

 None, as the theme service manages a browser preference; nothing here reaches a model request.
--- a/packages/client/ui-theme/README.zh.md
+++ b/packages/client/ui-theme/README.zh.md
@@ -4,6 +4,12 @@

 主题插件：基于 --dsw-* token 基础样式表（静态尺度 + 别名语义层）的 ThemeService。该服务拥有主题偏好（`light`／`dark`／`system`，以 `dsh.theme` 为键持久化），将 `system` 通过 `prefers-color-scheme` 解析为实际主题，并发布不可变的 `ThemeSnapshot`，通过 `theme/change` 事件通知变化；它绝不接触 DOM：ui-layout 的呈现器会应用解析后的快照（`html { color-scheme }`、`body[data-ds-dark-theme]`，以及主题的别名 token 内联变量）。契约：api-contracts v3 §8。

+`src/styles/` 下有五张样式表，全部由 web 壳的 `base.css` 导入：`base.css`、`design-platform.css`、`scrollbar.css`、`gradient-shadow-text.css` 与 `shiki.css`。`scrollbar.css` 是 `--dsw-alias-scrollbar-*` token 的唯一消费方，必须排在声明这些 token 的 `design-platform.css` 之后。
+
+滚动条重新绑定契约：`scrollbar.css` 在 `body` 上把 `--dsh-scrollbar-thumb` 与 `--dsh-scrollbar-thumb-hover` 绑定到 l1（基础表面）token，两条渲染路径都读取这一组变量。抬升表面（菜单、浮层、对话框）在自己的容器上设置 `--dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2)` 与 `--dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2)`；一次重新绑定即可为引擎实际走的那条路径换色。
+
+两条路径在构造上互斥。`scrollbar-width`／`scrollbar-color` 写在 `@supports not selector(::-webkit-scrollbar)` 之内，因为这两个属性只要取非 `auto` 值，Chromium 与 Safari 就会丢弃该元素上的全部 `::-webkit-scrollbar*` 规则，`::-webkit-scrollbar-thumb:hover` 也在其中——若无条件地同时声明，`--dsh-scrollbar-thumb-hover` 在任何引擎上都不会被渲染。因此 Firefox 走标准属性，WebKit 系引擎走伪元素，hover token 只经由伪元素这条路径渲染。推理过程与实测计算值见[滚动条 Agent Note](../../../.agents/notes/implemented/bug-fix/2026-07-28-themed-scrollbars-and-reserved-gutter.md)。
+
 ## 模型体验

 无。主题服务管理浏览器偏好；这里没有任何内容进入模型请求。
--- a/packages/client/ui-theme/src/styles/scrollbar.css
+++ b/packages/client/ui-theme/src/styles/scrollbar.css
@@ -0,0 +1,85 @@
+/* Scrollbar skin: the sole consumer of the four --dsw-alias-scrollbar-*
+ * tokens. Without it every scrolling region renders the UA scrollbar, which
+ * ignores the theme — a light native bar over the dark palette.
+ *
+ * The rules sit on `body`, not `html`: design-platform.css declares the
+ * --dsw-alias-* tokens on `body` (and the dark overrides on
+ * `body[data-ds-dark-theme]`), and custom properties only inherit downward,
+ * so an `html` rule resolves them to the guaranteed-invalid value and
+ * `scrollbar-color` falls back to `auto`.
+ *
+ * Surfaces pick their elevation by rebinding --dsh-scrollbar-thumb{,-hover}:
+ * the l1 pair here is the base-surface default, and an elevated surface
+ * (menu, popover, dialog) rebinds to the l2 pair on its own container. Both
+ * rendering paths below read the indirection, so one rebind reaches whichever
+ * path the engine took. */
+
+body {
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l1);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l1);
+}
+
+/* The two paths are mutually exclusive, and the gate is load-bearing rather
+   than defensive. A non-`auto` `scrollbar-width` or `scrollbar-color` makes
+   Chromium and Safari drop every `::-webkit-scrollbar*` rule for that
+   element, including `::-webkit-scrollbar-thumb:hover` — measured in chromium
+   as an 8px `::-webkit-scrollbar` width taking effect on its own and being
+   ignored as soon as `scrollbar-width: thin` is added. Declaring both
+   unconditionally therefore leaves the hover tokens with no rendering at all,
+   because the engines that implement the hover pseudo-element are exactly the
+   ones the standard properties silence, and Firefox has no hover
+   pseudo-element to fall back on.
+
+   `not selector(::-webkit-scrollbar)` is true only where the pseudo-element
+   is unimplemented, so Firefox takes the standard path and WebKit-based
+   engines take the pseudo-element path. An engine too old for the
+   `selector()` function makes the condition invalid, which evaluates false
+   and selects the pseudo-element path — the correct side for the pre-16.4
+   Safari that is the realistic case. */
+@supports not selector(::-webkit-scrollbar) {
+  /* Declared on every element rather than inherited from `body`. Inheriting
+     would pass down the COLOUR already substituted at `body`, so a descendant
+     rebinding --dsh-scrollbar-thumb could not change it; re-declaring makes
+     each element substitute the variable as it sees it, which is what gives
+     an elevated surface a working rebind. `scrollbar-width` is not an
+     inherited property at all, so it needs the per-element declaration
+     regardless.
+
+     No hover counterpart exists on this path: `scrollbar-color` states one
+     thumb colour and the engine derives its own hover treatment. */
+  body,
+  body * {
+    scrollbar-width: thin;
+    scrollbar-color: var(--dsh-scrollbar-thumb) transparent;
+  }
+}
+
+/* Not gated in turn: an engine that does not implement these pseudo-elements
+   drops the rules as unknown selectors, so the gate would only restate what
+   selector matching already does. Not inherited either, hence the unscoped
+   selectors. */
+::-webkit-scrollbar {
+  width: 8px;
+  height: 8px;
+}
+
+/* Track stays transparent so the thumb reads against whatever surface scrolls
+   under it; only the thumb carries a token colour. */
+::-webkit-scrollbar-track {
+  background: transparent;
+}
+
+::-webkit-scrollbar-thumb {
+  border-radius: 4px;
+  background: var(--dsh-scrollbar-thumb);
+}
+
+::-webkit-scrollbar-thumb:hover {
+  background: var(--dsh-scrollbar-thumb-hover);
+}
+
+/* Both scrollbars meeting in a corner: no separate token, so the corner
+   matches the transparent track rather than the UA's opaque default. */
+::-webkit-scrollbar-corner {
+  background: transparent;
+}
--- a/packages/client/ui-theme/tests/scrollbar-styles.spec.ts
+++ b/packages/client/ui-theme/tests/scrollbar-styles.spec.ts
@@ -0,0 +1,506 @@
+/**
+ * Scrollbar stylesheet contract, asserted against the CSS text on disk: every
+ * --dsw-alias-scrollbar-* token design-platform.css defines has a consumer,
+ * scrollbar.css binds the base-surface pair through the rebindable
+ * indirection, and elevated surfaces rebind that indirection in complete
+ * pairs. The expected token set is scanned out of design-platform.css, so
+ * adding, renaming, or dropping a scrollbar token moves these assertions with
+ * it.
+ */
+import { readdirSync, readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { describe, expect, it } from 'vitest'
+
+/** One flattened CSS rule: its comma-separated selector parts and its declarations in source order. */
+interface CssRule {
+  selectors: string[]
+  declarations: [property: string, value: string][]
+}
+
+const STYLES = new URL('../src/styles/', import.meta.url)
+const PACKAGES_DIR = fileURLToPath(new URL('../../../', import.meta.url))
+const read = (name: string): string => readFileSync(fileURLToPath(new URL(name, STYLES)), 'utf8')
+
+const platformCss = read('design-platform.css')
+const scrollbarCss = read('scrollbar.css')
+
+/** Body attribute selecting the dark palette; ui-layout's ThemePresenter sets it. */
+const DARK_ATTRIBUTE = '[data-ds-dark-theme]'
+/** Alias tokens under test: the prefix the elevation pairs share. */
+const TOKEN_PREFIX = '--dsw-alias-scrollbar-'
+/** Prefix of the rebindable indirection scrollbar.css owns. */
+const INDIRECTION_PREFIX = '--dsh-scrollbar-'
+
+/**
+ * Flatten a stylesheet into rules. Whitespace, declaration order, and trailing
+ * semicolons are normalized away; nesting and at-rules are not handled, which
+ * no sheet under test uses for scrollbar declarations.
+ * @param css - stylesheet text.
+ * @returns one entry per rule, in source order.
+ */
+function parseRules(css: string): CssRule[] {
+  const withoutComments = css.replace(/\/\*[\s\S]*?\*\//g, ' ')
+  const rules: CssRule[] = []
+  // Destructuring defaults only satisfy noUncheckedIndexedAccess; both groups
+  // are unconditional in the pattern.
+  for (const [, selector = '', body = ''] of withoutComments.matchAll(/([^{}]+)\{([^{}]*)\}/g)) {
+    const declarations = body
+      .split(';')
+      .map(part => part.trim())
+      .filter(part => part.includes(':'))
+      .map((part): [string, string] => {
+        const colon = part.indexOf(':')
+        return [part.slice(0, colon).trim(), part.slice(colon + 1).trim()]
+      })
+    rules.push({ selectors: selector.split(',').map(part => part.trim()), declarations })
+  }
+  return rules
+}
+
+/**
+ * Half-open source span of one at-rule's block, excluding its prelude.
+ * @param css - stylesheet text.
+ * @param prelude - exact at-rule prelude to locate, without the opening brace.
+ * @returns the block's brace offsets, or undefined when the prelude is absent.
+ */
+function atRuleBlock(css: string, prelude: string): { start: number; end: number } | undefined {
+  const opening = css.indexOf(`${prelude} {`)
+  if (opening === -1) return undefined
+  const start = css.indexOf('{', opening)
+  let depth = 0
+  for (let index = start; index < css.length; index += 1) {
+    if (css[index] === '{') depth += 1
+    else if (css[index] === '}') {
+      depth -= 1
+      if (depth === 0) return { start, end: index }
+    }
+  }
+  throw new Error(`unbalanced braces after ${prelude}`)
+}
+
+/**
+ * Custom-property names a value reads.
+ * @param value - declaration value, possibly with nested var() calls.
+ * @returns every referenced custom-property name, in source order.
+ */
+function varReferences(value: string): string[] {
+  return [...value.matchAll(/var\(\s*(--[\w-]+)/g)].map(([, name = '']) => name)
+}
+
+/**
+ * Every CSS file shipped as package source, excluding build output and
+ * installed dependencies.
+ * @returns absolute paths of the stylesheets under packages/.
+ */
+function packageStylesheets(): string[] {
+  const found: string[] = []
+  const walk = (dir: string): void => {
+    for (const entry of readdirSync(dir, { withFileTypes: true })) {
+      const path = join(dir, entry.name)
+      if (entry.isDirectory()) {
+        if (entry.name !== 'node_modules' && entry.name !== 'lib' && entry.name !== 'dist') walk(path)
+      } else if (entry.name.endsWith('.css')) found.push(path)
+    }
+  }
+  walk(PACKAGES_DIR)
+  return found
+}
+
+/**
+ * Tokens a stylesheet reads through its rendering declarations, following its
+ * own custom-property definitions transitively so a token reached only through
+ * an indirection counts. The walk starts from the standard-property
+ * declarations, so a defined-but-unread indirection contributes nothing.
+ * @param rules - parsed rules of one stylesheet.
+ * @returns every `--dsw-*` token the sheet's rendering declarations depend on.
+ */
+function tokensRendered(rules: CssRule[]): Set<string> {
+  const definitions = new Map<string, string>()
+  const pending: string[] = []
+  for (const rule of rules) {
+    for (const [property, value] of rule.declarations) {
+      if (property.startsWith('--')) definitions.set(property, value)
+      else pending.push(value)
+    }
+  }
+  const reached = new Set<string>()
+  const visited = new Set<string>()
+  while (pending.length > 0) {
+    for (const name of varReferences(pending.pop()!)) {
+      if (name.startsWith('--dsw-')) reached.add(name)
+      if (visited.has(name)) continue
+      visited.add(name)
+      const definition = definitions.get(name)
+      if (definition !== undefined) pending.push(definition)
+    }
+  }
+  return reached
+}
+
+const platformRules = parseRules(platformCss)
+const scrollbarRules = parseRules(scrollbarCss)
+const sorted = (names: Iterable<string>): string[] => [...names].sort()
+
+/**
+ * Scrollbar tokens defined by the rules whose selectors carry (or do not
+ * carry) the dark palette attribute.
+ * @param dark - true to scan the dark blocks, false to scan the light blocks.
+ * @returns the scrollbar token names defined there.
+ */
+function definedTokens(dark: boolean): Set<string> {
+  const names = new Set<string>()
+  for (const rule of platformRules) {
+    if (rule.selectors.every(selector => selector.includes(DARK_ATTRIBUTE)) !== dark) continue
+    for (const [property] of rule.declarations) {
+      if (property.startsWith(TOKEN_PREFIX)) names.add(property)
+    }
+  }
+  return names
+}
+
+const lightTokens = definedTokens(false)
+const darkTokens = definedTokens(true)
+const allTokens = new Set([...lightTokens, ...darkTokens])
+
+/** Every scrollbar token any package stylesheet references, mapped to the files referencing it. */
+const referencedTokens = new Map<string, string[]>()
+/** Every indirection property any package stylesheet outside ui-theme declares, mapped to its declaring rules. */
+const rebindRules: { file: string; rule: CssRule }[] = []
+/**
+ * What one stylesheet contributes to the elevated-surface question: which
+ * elevated surfaces it paints, whether any rule scrolls, and whether it
+ * rebinds. Kept per file rather than per rule because the elevated card and the
+ * descendant that actually scrolls are separate rules in the same sheet, and
+ * CSS text does not express which contains which.
+ */
+interface SheetSurfaces {
+  /** Elevated surface tokens this sheet paints anywhere. */
+  elevated: Set<string>
+  /** True when some rule declares `overflow*: auto|scroll`. */
+  scrolls: boolean
+  /** True when some rule rebinds the indirection. */
+  rebinds: boolean
+}
+const sheetSurfaces = new Map<string, SheetSurfaces>()
+
+/** Properties whose `auto`/`scroll` value makes a rule a scroll container. */
+const OVERFLOW_PROPERTIES = ['overflow', 'overflow-x', 'overflow-y']
+/** Properties that paint a surface, and so identify the elevation a rule sits on. */
+const SURFACE_PROPERTIES = ['background', 'background-color']
+/**
+ * Token families that name a SURFACE — a background an element is drawn on, and
+ * so something a scrollbar can sit against. `--dsw-alias-button-*`,
+ * `--dsw-alias-interactive-*`, and `--dsw-alias-markdown-*` reach the same dark
+ * elevation rungs while naming a control or an inline span, which no scroll
+ * container renders its bar against (ChatView's floating `.toBottom` pill,
+ * CodeBlock's banner). Family, not geometry: a floating button legitimately
+ * carries a radius, a shadow, and a fixed size, so shape cannot separate them.
+ */
+const SURFACE_TOKEN_PATTERN = /^--dsw-(?:alias-bg-|specific-)/
+
+/**
+ * The palette's own dark elevation ladder, resolved from `design-platform.css`:
+ * `bg-layer-2` and `bg-layer-3` are the rungs above the base surfaces, and the
+ * l1/l2 scrollbar split encodes exactly that step. Reading it from the palette
+ * rather than from the sheets that happen to rebind is what lets the check flag
+ * a surface NOBODY has rebound yet.
+ * @returns surface tokens whose dark value sits on an elevated rung.
+ */
+function elevatedRungs(): Set<string> {
+  const definitions = new Map<string, string>()
+  for (const rule of platformRules) {
+    // Dark declarations come later in the sheet and overwrite the light ones,
+    // which is the palette this distinction exists in.
+    for (const [property, value] of rule.declarations) definitions.set(property, value)
+  }
+  const resolve = (name: string): string => {
+    const seen = new Set<string>()
+    let current = name
+    while (definitions.has(current) && !seen.has(current)) {
+      seen.add(current)
+      const value = definitions.get(current)!
+      const [reference] = varReferences(value)
+      if (reference === undefined) return value
+      current = reference
+    }
+    return current
+  }
+  const rungs = new Set([resolve('--dsw-alias-bg-layer-2'), resolve('--dsw-alias-bg-layer-3')])
+  const tokens = new Set<string>()
+  for (const name of definitions.keys()) {
+    if (SURFACE_TOKEN_PATTERN.test(name) && rungs.has(resolve(name))) tokens.add(name)
+  }
+  return tokens
+}
+
+const elevatedSurfaces = elevatedRungs()
+
+for (const file of packageStylesheets()) {
+  const rules = parseRules(readFileSync(file, 'utf8'))
+  const surfaces: SheetSurfaces = { elevated: new Set(), scrolls: false, rebinds: false }
+  for (const rule of rules) {
+    let rebinds = false
+    const ruleSurfaces: string[] = []
+    for (const [property, value] of rule.declarations) {
+      if (property.startsWith(INDIRECTION_PREFIX) && file !== fileURLToPath(new URL('scrollbar.css', STYLES))) rebinds = true
+      if (OVERFLOW_PROPERTIES.includes(property) && /\b(?:auto|scroll)\b/.test(value)) surfaces.scrolls = true
+      if (SURFACE_PROPERTIES.includes(property)) ruleSurfaces.push(...varReferences(value))
+      for (const token of varReferences(value)) {
+        if (!token.startsWith(TOKEN_PREFIX)) continue
+        referencedTokens.set(token, [...referencedTokens.get(token) ?? [], file])
+      }
+    }
+    for (const token of ruleSurfaces) {
+      if (elevatedSurfaces.has(token)) surfaces.elevated.add(token)
+    }
+    if (rebinds) {
+      rebindRules.push({ file, rule })
+      surfaces.rebinds = true
+    }
+  }
+  sheetSurfaces.set(file, surfaces)
+}
+
+describe('design-platform.css scrollbar tokens', () => {
+  it('defines the same scrollbar token set in the light and the dark block', () => {
+    // A token present only in the light block silently keeps its light value
+    // under the dark palette, since the dark block only overrides.
+    expect(allTokens.size).toBeGreaterThan(0)
+    expect(sorted(lightTokens)).toEqual(sorted(allTokens))
+    expect(sorted(darkTokens)).toEqual(sorted(allTokens))
+  })
+
+  it('resolves every scrollbar token to a static scale value, not to another alias', () => {
+    // The alias layer is the only indirection in the token sheet: an alias
+    // pointing at a second alias makes the dark override order-dependent.
+    for (const rule of platformRules) {
+      for (const [property, value] of rule.declarations) {
+        if (!property.startsWith(TOKEN_PREFIX)) continue
+        for (const reference of varReferences(value)) {
+          expect(reference, `${property}: ${value}`).toMatch(/^--dsw-static-/)
+        }
+      }
+    }
+  })
+})
+
+describe('scrollbar token consumers', () => {
+  it('every defined scrollbar token is referenced by some package stylesheet', () => {
+    // Before scrollbar.css existed these tokens had no consumer at all and
+    // every scroll container rendered the unthemed UA bar. A fifth token, or a
+    // rename on one side only, leaves the new name unreferenced here.
+    expect(sorted(referencedTokens.keys())).toEqual(sorted(allTokens))
+  })
+
+  it('every referenced scrollbar token is defined in design-platform.css', () => {
+    // A dangling var() renders the UA default instead of failing loudly, so a
+    // rename has to move the reference and the definition together.
+    for (const [token, files] of referencedTokens) {
+      expect(allTokens, files.join(', ')).toContain(token)
+    }
+  })
+})
+
+describe('scrollbar.css base-surface binding', () => {
+  const rendered = tokensRendered(scrollbarRules)
+
+  it('renders the l1 pair through the rebindable indirection', () => {
+    // l1 is the base-surface default the indirection resolves to; the
+    // indirection only counts as bound when a rendering declaration reads it.
+    expect(rendered).toContain(`${TOKEN_PREFIX}bg-l1`)
+    expect(rendered).toContain(`${TOKEN_PREFIX}hover-l1`)
+  })
+
+  it('routes the standard property and the WebKit thumb through the same indirection', () => {
+    // A rebind on an elevated container has to move the Firefox and the WebKit
+    // rendering together, which only holds while both read the same variable.
+    const declaration = (property: string, selectorPart: string): string | undefined => scrollbarRules
+      .filter(rule => rule.selectors.includes(selectorPart))
+      .flatMap(rule => rule.declarations)
+      .findLast(([name]) => name === property)?.[1]
+    const thumbColor = declaration('scrollbar-color', 'body')
+    expect(thumbColor).toBeDefined()
+    const indirection = varReferences(thumbColor!)[0]
+    expect(indirection).toBe(`${INDIRECTION_PREFIX}thumb`)
+    expect(varReferences(declaration('background', '::-webkit-scrollbar-thumb')!)).toEqual([indirection])
+  })
+})
+
+describe('scrollbar.css selectors', () => {
+  const scrollbarColorSelectors = scrollbarRules
+    .filter(rule => rule.declarations.some(([property]) => property === 'scrollbar-color'))
+    .flatMap(rule => rule.selectors)
+
+  it('declares scrollbar-color only where the body-scoped tokens are visible', () => {
+    // design-platform.css defines the alias tokens on `body`, and custom
+    // properties inherit downward only: the same declaration on `html` or
+    // `:root` resolves to the guaranteed-invalid value, which computes
+    // scrollbar-color to `auto` and drops the theming entirely.
+    expect(scrollbarColorSelectors.length).toBeGreaterThan(0)
+    for (const selector of scrollbarColorSelectors) {
+      expect(selector, selector).toMatch(/^body\b/)
+    }
+  })
+
+  it('defines the indirection where the alias tokens are visible', () => {
+    const definesIndirection = ([property, value]: [string, string]): boolean =>
+      property.startsWith(INDIRECTION_PREFIX) && value.includes(TOKEN_PREFIX)
+    const hosts = scrollbarRules
+      .filter(rule => rule.declarations.some(definesIndirection))
+      .flatMap(rule => rule.selectors)
+    expect(hosts.length).toBeGreaterThan(0)
+    for (const selector of hosts) expect(selector, selector).toMatch(/^body\b/)
+  })
+
+  it('re-declares the scrollbar properties per element rather than inheriting them', () => {
+    // scrollbar-width is not an inherited property, and an inherited
+    // scrollbar-color carries the colour already substituted at `body`, which
+    // a descendant rebinding the indirection could no longer change.
+    expect(scrollbarColorSelectors).toContain('body *')
+    const widthSelectors = scrollbarRules
+      .filter(rule => rule.declarations.some(([property]) => property === 'scrollbar-width'))
+      .flatMap(rule => rule.selectors)
+    expect(widthSelectors).toContain('body *')
+  })
+})
+
+describe('scrollbar.css rendering paths', () => {
+  /** The gate prelude, spelled exactly as the sheet must spell it for the split to exist. */
+  const GATE = '@supports not selector(::-webkit-scrollbar)'
+  const withoutComments = scrollbarCss.replace(/\/\*[\s\S]*?\*\//g, ' ')
+  const gate = atRuleBlock(withoutComments, GATE)
+  /** Standard scrollbar properties, the ones whose non-`auto` values suppress the pseudo-elements. */
+  const STANDARD_PROPERTIES = ['scrollbar-width', 'scrollbar-color']
+
+  it('gates the standard properties behind the absence of the WebKit pseudo-element', () => {
+    // A non-`auto` scrollbar-width or scrollbar-color makes Chromium and
+    // Safari discard every ::-webkit-scrollbar* rule for that element,
+    // ::-webkit-scrollbar-thumb:hover included. Declaring both paths
+    // unconditionally therefore renders the hover token nowhere: the engines
+    // implementing the hover pseudo-element are exactly the ones the standard
+    // properties silence, and Firefox has no hover pseudo-element at all.
+    expect(gate, GATE).toBeDefined()
+    for (const property of STANDARD_PROPERTIES) {
+      const offsets = [...withoutComments.matchAll(new RegExp(String.raw`(^|[;{\s])${property}\s*:`, 'g'))]
+        .map(match => match.index)
+      expect(offsets.length, property).toBeGreaterThan(0)
+      for (const offset of offsets) {
+        expect(offset, `${property} outside ${GATE}`).toBeGreaterThan(gate!.start)
+        expect(offset, `${property} outside ${GATE}`).toBeLessThan(gate!.end)
+      }
+    }
+  })
+
+  it('leaves the WebKit pseudo-element rules outside the gate', () => {
+    // Gating these in turn would only restate selector matching: an engine
+    // without the pseudo-elements drops the rules as unknown selectors. Inside
+    // the gate they would be dropped by the engines that do implement them,
+    // which is every engine that can render them.
+    const offsets = [...withoutComments.matchAll(/::-webkit-scrollbar/g)]
+      .map(match => match.index)
+      .filter(offset => withoutComments.slice(offset).search(/^[\w:-]*\s*[,{]/) === 0)
+    expect(offsets.length).toBeGreaterThan(0)
+    for (const offset of offsets) {
+      expect(offset > gate!.start && offset < gate!.end, `::-webkit-scrollbar rule inside ${GATE}`).toBe(false)
+    }
+  })
+
+  it('renders the hover token only through the pseudo-element path', () => {
+    // The standard path has no hover counterpart — scrollbar-color states one
+    // thumb colour and the engine derives its own hover treatment — so the
+    // hover indirection has to be read outside the gate or it renders nowhere.
+    const hoverOffsets = [...withoutComments.matchAll(new RegExp(String.raw`var\(\s*${INDIRECTION_PREFIX}thumb-hover`, 'g'))]
+      .map(match => match.index)
+    expect(hoverOffsets.length).toBeGreaterThan(0)
+    for (const offset of hoverOffsets) {
+      expect(offset > gate!.start && offset < gate!.end, 'hover indirection read inside the gate').toBe(false)
+    }
+  })
+})
+
+describe('elevated surface rebinds', () => {
+  it('at least one surface rebinds the indirection', () => {
+    expect(rebindRules.length).toBeGreaterThan(0)
+  })
+
+  it('each rebinding rule sets the thumb and the hover variable together', () => {
+    // A surface rebinding only the resting colour keeps the l1 hover colour,
+    // so the elevation is wrong only while the pointer is over the thumb.
+    for (const { file, rule } of rebindRules) {
+      const properties = rule.declarations.map(([property]) => property).filter(property => property.startsWith(INDIRECTION_PREFIX))
+      expect(sorted(properties), `${file} ${rule.selectors.join(', ')}`).toEqual([
+        `${INDIRECTION_PREFIX}thumb-hover`, `${INDIRECTION_PREFIX}thumb`,
+      ].sort())
+    }
+  })
+
+  it('each rebinding rule binds the indirection names scrollbar.css renders', () => {
+    // A misspelled property name declares an unused variable, and the surface
+    // silently keeps the base-surface colour.
+    const rendered = new Set(
+      scrollbarRules
+        .flatMap(rule => rule.declarations)
+        .filter(([property]) => !property.startsWith('--'))
+        .flatMap(([, value]) => varReferences(value))
+        .filter(name => name.startsWith(INDIRECTION_PREFIX)),
+    )
+    for (const { file, rule } of rebindRules) {
+      for (const [property] of rule.declarations) {
+        if (property.startsWith(INDIRECTION_PREFIX)) expect(rendered, `${file}: ${property}`).toContain(property)
+      }
+    }
+  })
+
+  it('every rebind targets the l2 elevation pair', () => {
+    for (const { file, rule } of rebindRules) {
+      for (const [property, value] of rule.declarations) {
+        if (!property.startsWith(INDIRECTION_PREFIX)) continue
+        for (const token of varReferences(value)) {
+          expect(token, `${file}: ${property}`).toMatch(/-l2$/)
+        }
+      }
+    }
+  })
+
+  it('resolves the elevated surface set from the palette ladder', () => {
+    // The set has to come from the palette, not from the sheets that happen to
+    // rebind: derived from rebinds it can only confirm what someone already
+    // remembered, and a surface nobody has rebound yet — the case the check
+    // exists for — would define itself as unelevated. Anchoring it here means a
+    // new palette token on an elevated rung is in scope the moment it is
+    // defined. `--dsw-specific-tip` is the regression that proved the point: it
+    // resolves to the same dark rung as the menu surface, and the Todo panel
+    // scrolled on it unrebound while a rebind-derived set stayed green.
+    expect(elevatedSurfaces).toContain('--dsw-alias-bg-layer-2')
+    expect(elevatedSurfaces).toContain('--dsw-alias-bg-layer-3')
+    expect(elevatedSurfaces).toContain('--dsw-specific-menu')
+    expect(elevatedSurfaces).toContain('--dsw-specific-input-major')
+    expect(elevatedSurfaces).toContain('--dsw-specific-tip')
+    // Base surfaces stay out, or every scroll container would be in scope and
+    // the check would say nothing.
+    expect(elevatedSurfaces).not.toContain('--dsw-alias-bg-base')
+    expect(elevatedSurfaces).not.toContain('--dsw-alias-bg-layer-1')
+  })
+
+  it('every sheet that scrolls on an elevated surface rebinds', () => {
+    // The failure this closes: a scroll container on an elevated surface that
+    // nobody remembered to rebind renders the l1 thumb, which differs from l2
+    // only in the dark palette and only for that one surface — invisible both in
+    // review and in a light-palette screenshot. Four sheets shipped that way
+    // (ui-primitives Menu, InputBar, QuestionComposer, TodoPanel) and review
+    // caught them by hand, which is what this replaces.
+    //
+    // Surface-level, not element-level: the elevated card and the descendant
+    // that scrolls are separate rules, and CSS text does not say which contains
+    // which. What keeps that from over-reporting is the token FAMILY: only
+    // `--dsw-alias-bg-*` and `--dsw-specific-*` name a surface, so a floating
+    // button or an inline code span reaching the same rung is out of scope
+    // (ChatView's `.toBottom`, CodeBlock's banner). Geometry cannot make that
+    // call — a floating button carries a radius, a shadow, and a fixed size.
+    for (const [file, surfaces] of sheetSurfaces) {
+      if (!surfaces.scrolls || surfaces.rebinds) continue
+      expect([...surfaces.elevated], `${file} scrolls on an elevated surface without rebinding`).toEqual([])
+    }
+  })
+})
--- a/packages/client/ui-trajectory/tests/views.spec.tsx
+++ b/packages/client/ui-trajectory/tests/views.spec.tsx
@@ -77,6 +77,7 @@ function standaloneProps(nodes: ConversationSnapshot['nodes']): ConvViewProps {
    useSession: fakeSession(nodes).useSession,
    useSessions: emptySessions(),
    useWorkspaces: emptyWorkspaces(),
+    useProjection: (() => undefined) as never,
  } as unknown as ConvViewProps
 }

@@ -135,6 +136,7 @@ function mount(slots: SlotsService, nodes: ConversationSnapshot['nodes'] = NODES
      useSession={useSession}
      useSessions={emptySessions()}
      useWorkspaces={emptyWorkspaces()}
+      useProjection={(() => undefined)}
      useStore={bindSnapshotSelector(chat)}
      actions={chat.actions}
      renderSlot={renderSlot}
@@ -330,6 +332,7 @@ describe('deriveSubSpans (waterfall lanes)', () => {
      useSession: bindSnapshotSelector(store) as unknown as UseSession<ConversationSnapshot>,
      useSessions: emptySessions(),
      useWorkspaces: emptyWorkspaces(),
+      useProjection: (() => undefined) as never,
    } as unknown as ConvViewProps
    const view = render(createElement(WaterfallView as FC<ConvViewProps>, props))
    const lane = view.container.querySelector('[data-subspan]')
@@ -356,6 +359,7 @@ describe('deriveSubSpans (waterfall lanes)', () => {
      useSession: bindSnapshotSelector(store) as unknown as UseSession<ConversationSnapshot>,
      useSessions: emptySessions(),
      useWorkspaces: emptyWorkspaces(),
+      useProjection: (() => undefined) as never,
    } as unknown as ConvViewProps
    const view = render(createElement(WaterfallView as FC<ConvViewProps>, props))
    const bar = view.container.querySelector('[data-timing="unknown"]')
--- a/packages/client/ui-workspace/src/client/WorkspaceBrowser.module.css
+++ b/packages/client/ui-workspace/src/client/WorkspaceBrowser.module.css
@@ -208,6 +208,13 @@
  min-height: 0;
  overflow-y: auto;
  padding-bottom: 12px;
+  /* Row trailing content (the relative time, and the hover action buttons
+     that replace it) sits flush against the row's 8px right padding, so an
+     overlaid scrollbar covers it. Reserving the gutter keeps the bar beside
+     the rows instead of on top of them; `stable` holds the reservation when
+     the list is short enough not to scroll, so expanding a group does not
+     shift every row left. */
+  scrollbar-gutter: stable;
 }

 /* One workspace section: header row + expanded session run. Rows inside
--- a/packages/client/ui-workspace/tests/browser-styles.spec.ts
+++ b/packages/client/ui-workspace/tests/browser-styles.spec.ts
@@ -0,0 +1,48 @@
+/**
+ * WorkspaceBrowser scroll-region style contract, asserted against the CSS text
+ * on disk: the session list reserves its scrollbar gutter so the scrollbar
+ * cannot overlay row trailing content, and reserves it whether or not the list
+ * currently overflows so expanding a group does not shift rows sideways.
+ */
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import { describe, expect, it } from 'vitest'
+
+const css = readFileSync(fileURLToPath(new URL('../src/client/WorkspaceBrowser.module.css', import.meta.url)), 'utf8')
+
+/**
+ * Declarations of one class rule, keyed by property with whitespace collapsed.
+ * Declaration order and trailing semicolons are normalized away.
+ * @param className - local class name, without the leading dot.
+ * @returns the rule's declarations, or undefined when no such rule exists.
+ */
+function declarations(className: string): Map<string, string> | undefined {
+  const withoutComments = css.replace(/\/\*[\s\S]*?\*\//g, ' ')
+  const match = new RegExp(String.raw`(^|[\s,}])\.${className}\s*\{([^{}]*)\}`).exec(withoutComments)
+  if (match === null) return undefined
+  const found = new Map<string, string>()
+  // The body group is unconditional in the pattern; the fallback only satisfies
+  // noUncheckedIndexedAccess.
+  for (const part of (match[2] ?? '').split(';')) {
+    const colon = part.indexOf(':')
+    if (colon === -1) continue
+    found.set(part.slice(0, colon).trim(), part.slice(colon + 1).trim().replace(/\s+/g, ' '))
+  }
+  return found
+}
+
+describe('WorkspaceBrowser.module.css list', () => {
+  const list = declarations('list')
+
+  it('is the scrolling region', () => {
+    expect(list).toBeDefined()
+    expect(list!.get('overflow-y')).toBe('auto')
+  })
+
+  it('reserves the scrollbar gutter unconditionally', () => {
+    // Row trailing content sits flush against the row's right padding, so an
+    // overlay scrollbar covers it. `stable` keeps the reservation when the list
+    // is short enough not to scroll, so expanding a group does not shift rows.
+    expect(list!.get('scrollbar-gutter')).toBe('stable')
+  })
+})
--- a/packages/client/web-react/src/scoped-slots.tsx
+++ b/packages/client/web-react/src/scoped-slots.tsx
@@ -10,7 +10,7 @@ import {
 } from '@deepseek-ai/dsh-client-ui-slots'
 import {
  HostContext, SessionMaybeProvider, SessionProvider, SlotAssemblyError, maybeObservableHook,
-  observableHook, useHost, useSessionMaybeProvideInfo,
+  observableHook, projectionHook, useHost, useSessionMaybeProvideInfo,
 } from './session-provider.tsx'

 type InjectedProps = Record<string, unknown>
@@ -238,6 +238,9 @@ function standardKit(
    }
    Object.assign(kit, info.props)
    kit['sessionId'] = info.sessionId
+    // The useProjection seat (fifth framework hook): key-addressed cell
+    // reader, bound per provide bundle (cached by info identity).
+    kit['useProjection'] = projectionHook(info)
  }
  const store = scope === 'session-maybe' && info?.sessionId === undefined
    ? undefined
--- a/packages/client/web-react/src/session-provider.tsx
+++ b/packages/client/web-react/src/session-provider.tsx
@@ -83,6 +83,39 @@ function useAbsentSnapshot<S>(_selector: (snapshot: never) => S, _equal?: (a: S,
  return undefined
 }

+/**
+ * The useProjection framework seat (session-projection RFC), one bound
+ * function per provide bundle (cached by info identity — components may hold
+ * it across renders). Key-addressed: the key resolves a per-session value
+ * face off the projection store; the bound selector hook comes from the same
+ * per-source cache as every other kit hook, so exactly one uSES subscription
+ * runs per call and the subscribe reference stays stable per key. A key no
+ * baseline or frame has carried (or a no-session bundle) reads `undefined` —
+ * capability absence — keeping the hook order constant.
+ */
+export function projectionHook(info: SessionMaybeProvideInfo): (
+  key: string, selector?: (value: unknown) => unknown, eq?: (a: unknown, b: unknown) => boolean,
+) => unknown {
+  let hook = projectionHookCache.get(info)
+  if (hook === undefined) {
+    hook = (key, selector, eq) => {
+      // The no-session (faceless) branch binds the shared absent source so
+      // the caller's selector still runs over `undefined` (absence flows
+      // through the selector) and the uSES call count stays constant.
+      const useValue = observableHook(info.projections?.faceOf(key) ?? absentSource)
+      // Whole values are finished wire payloads (reference changes only when
+      // a frame or baseline lands), so the identity selector needs no
+      // equality function.
+      return useValue(selector ?? (value => value), eq)
+    }
+    projectionHookCache.set(info, hook)
+  }
+  return hook
+}
+const projectionHookCache = new WeakMap<SessionMaybeProvideInfo, (
+  key: string, selector?: (value: unknown) => unknown, eq?: (a: unknown, b: unknown) => boolean,
+) => unknown>()
+
 /**
 * Root-level binding provider. It follows current selection without a key, so
 * session-maybe entries retain their React identity while the context value
--- a/packages/client/web-react/tests/use-projection.spec.tsx
+++ b/packages/client/web-react/tests/use-projection.spec.tsx
@@ -0,0 +1,128 @@
+// @vitest-environment jsdom
+/**
+ * useProjection standard-kit delivery (session-projection RFC): the fifth
+ * framework hook seat rides the same provide channel as useSession — a
+ * session slot component receives `useProjection` in its kit, key-addressed
+ * over the bundle's projection face; unresolved keys (no value, no face, no
+ * session) uniformly read `undefined`; live value changes re-render; the
+ * selector overload runs over the whole value.
+ */
+import { describe, expect, it } from 'vitest'
+import { act, render } from '@testing-library/react'
+import type { SessionMaybeProvideInfo, StoredEntry } from '@deepseek-ai/dsh-client-ui-slots'
+import { createSlotRenderer, type SlotRendererHost } from '@deepseek-ai/dsh-client-web-react'
+
+function observable<T>(initial: T) {
+  let value = initial
+  const subs = new Set<() => void>()
+  return {
+    getSnapshot: () => value,
+    subscribe: (fn: () => void) => { subs.add(fn); return () => { subs.delete(fn) } },
+    set: (next: T) => { value = next; for (const fn of [...subs]) fn() },
+  }
+}
+
+type UseProjectionProp = (key: string, selector?: (v: unknown) => unknown) => unknown
+
+function makeHost() {
+  const absentInfo: SessionMaybeProvideInfo = { sessionId: undefined, hooks: { session: undefined }, props: {} }
+  const provide = observable<SessionMaybeProvideInfo>(absentInfo)
+  const cells = new Map<string, ReturnType<typeof observable<unknown>>>()
+  /** Store-parallel face: always defined per key; an unseen key snapshots undefined. */
+  const absent = { getSnapshot: () => undefined, subscribe: () => () => {} }
+  const sessionEntries: StoredEntry[] = []
+  let withFace = true
+  const rootEntry: StoredEntry = {
+    component: (props: { renderSlot: (key: string, owner: object) => React.ReactNode }) =>
+      <>{props.renderSlot('k.session', {})}</>,
+    options: {},
+    children: { 'k.session': { kind: 'single', scope: 'session' } },
+  }
+  const info = (id: string): SessionMaybeProvideInfo => ({
+    sessionId: id,
+    hooks: { session: { getSnapshot: () => ({ sid: id }), subscribe: () => () => {} } },
+    props: {},
+    ...(withFace ? { projections: { faceOf: (key: string) => cells.get(key) ?? absent } } : {}),
+  })
+  const host: SlotRendererHost = {
+    subscribe: () => () => {},
+    getVersion: () => 0,
+    entriesOf: key => key === 'root' ? [rootEntry] : sessionEntries,
+    specOf: key => key === 'k.session' ? { kind: 'single', scope: 'session' } : undefined,
+    isLive: () => true,
+    storeOf: () => undefined,
+    sessions: {
+      list: observable<unknown>({ ids: [] }),
+      provideInfo: provide,
+    },
+    workspaces: { list: observable<unknown>({ items: [] }) },
+  }
+  return {
+    host,
+    cells,
+    // Same driver surface as before the atomic provide source: set(id)
+    // publishes the resolved bundle (or the absent projection) through it.
+    current: { set: (id: string | undefined) => { provide.set(id === undefined ? absentInfo : info(id)) } },
+    dropFace: () => { withFace = false },
+    registerSession: (entry: StoredEntry) => { sessionEntries.push(entry) },
+  }
+}
+
+describe('useProjection standard-kit delivery', () => {
+  it('reads the projected value through the kit, undefined for unresolved keys, and follows live changes', () => {
+    const h = makeHost()
+    const cell = observable<unknown>({ marks: ['a'] })
+    h.cells.set('test/marks', cell)
+    const reads: Record<string, unknown>[] = []
+    h.registerSession({
+      component: (props: { useProjection: UseProjectionProp }) => {
+        reads.push({
+          marks: props.useProjection('test/marks'),
+          ghost: props.useProjection('test/ghost'),
+        })
+        return null
+      },
+      options: {},
+    })
+    render(<>{createSlotRenderer().renderRoot(h.host, {})}</>)
+    act(() => { h.current.set('s1') })
+    expect(reads.at(-1)).toEqual({ marks: { marks: ['a'] }, ghost: undefined })
+    // Live change re-renders with the new whole value.
+    act(() => { cell.set({ marks: ['a', 'b'] }) })
+    expect(reads.at(-1)).toEqual({ marks: { marks: ['a', 'b'] }, ghost: undefined })
+  })
+
+  it('runs the selector overload over the whole value (and over undefined when absent)', () => {
+    const h = makeHost()
+    h.cells.set('test/marks', observable<unknown>({ marks: ['x', 'y'] }))
+    const reads: unknown[] = []
+    h.registerSession({
+      component: (props: { useProjection: UseProjectionProp }) => {
+        reads.push(props.useProjection('test/marks', v => (v as { marks: string[] } | undefined)?.marks.length ?? -1))
+        reads.push(props.useProjection('test/ghost', v => (v === undefined ? 'absent' : 'present')))
+        return null
+      },
+      options: {},
+    })
+    render(<>{createSlotRenderer().renderRoot(h.host, {})}</>)
+    act(() => { h.current.set('s1') })
+    expect(reads.slice(-2)).toEqual([2, 'absent'])
+  })
+
+  it('treats a bundle without the projections face as all-absent (capability absence)', () => {
+    const h = makeHost()
+    h.cells.set('test/marks', observable<unknown>({ marks: ['a'] }))
+    h.dropFace()
+    const reads: unknown[] = []
+    h.registerSession({
+      component: (props: { useProjection: UseProjectionProp }) => {
+        reads.push(props.useProjection('test/marks'))
+        return null
+      },
+      options: {},
+    })
+    render(<>{createSlotRenderer().renderRoot(h.host, {})}</>)
+    act(() => { h.current.set('s1') })
+    expect(reads.at(-1)).toBeUndefined()
+  })
+})
--- a/packages/client/web/src/base.css
+++ b/packages/client/web/src/base.css
@@ -1,8 +1,10 @@
 /* Shell-owned global base: full-height mount plus the theme token sheets.
- * The four ui-theme sheets are the sole token source (--dsw-*); the shell
- * links them here so tokens exist before any plugin CSS lands. */
+ * The five ui-theme sheets are the sole token source (--dsw-*); the shell
+ * links them here so tokens exist before any plugin CSS lands. scrollbar.css
+ * follows design-platform.css because it reads that sheet's tokens. */
@import '@deepseek-ai/dsh-client-ui-theme/styles/base.css';
@import '@deepseek-ai/dsh-client-ui-theme/styles/design-platform.css';
+@import '@deepseek-ai/dsh-client-ui-theme/styles/scrollbar.css';
@import '@deepseek-ai/dsh-client-ui-theme/styles/gradient-shadow-text.css';
@import '@deepseek-ai/dsh-client-ui-theme/styles/shiki.css';

--- a/packages/client/web/tests/base-styles.spec.ts
+++ b/packages/client/web/tests/base-styles.spec.ts
@@ -0,0 +1,58 @@
+/**
+ * Shell base sheet contract, asserted against the CSS text on disk: base.css is
+ * where the ui-theme token sheets enter the bundle, every sheet it names exists,
+ * and scrollbar.css follows design-platform.css because it reads that sheet's
+ * tokens.
+ */
+import { existsSync, readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import { describe, expect, it } from 'vitest'
+
+const THEME_PACKAGE = '@deepseek-ai/dsh-client-ui-theme'
+const baseCss = readFileSync(fileURLToPath(new URL('../src/base.css', import.meta.url)), 'utf8')
+
+/**
+ * Import specifiers of the sheet, in source order. Quote style and surrounding
+ * whitespace are normalized away.
+ * @param css - stylesheet text.
+ * @returns each `@import` target in the order the sheet lists it.
+ */
+function importOrder(css: string): string[] {
+  // The destructuring default only satisfies noUncheckedIndexedAccess; the
+  // group is unconditional in the pattern.
+  return [...css.matchAll(/@import\s+['"]([^'"]+)['"]/g)].map(([, specifier = '']) => specifier)
+}
+
+/**
+ * Resolve a `<package>/styles/<file>` specifier to its path in the workspace.
+ * The theme package maps `./styles/*` to `./src/styles/*`, so the sheets stay
+ * on the source plane rather than needing a build.
+ * @param specifier - import specifier from base.css.
+ * @returns absolute path of the file the specifier names.
+ */
+function resolveThemeSheet(specifier: string): string {
+  const name = specifier.slice(`${THEME_PACKAGE}/styles/`.length)
+  return fileURLToPath(new URL(`../../ui-theme/src/styles/${name}`, import.meta.url))
+}
+
+const imports = importOrder(baseCss)
+
+describe('web shell base.css', () => {
+  it('imports every sheet from the theme package and each one exists', () => {
+    expect(imports.length).toBeGreaterThan(0)
+    for (const specifier of imports) {
+      expect(specifier.startsWith(`${THEME_PACKAGE}/styles/`), specifier).toBe(true)
+      expect(existsSync(resolveThemeSheet(specifier)), specifier).toBe(true)
+    }
+  })
+
+  it('imports the scrollbar sheet after the token sheet it reads', () => {
+    // Both sheets bind on `body`, so with scrollbar.css first the alias tokens
+    // would still resolve; the order encodes the dependency direction so a
+    // later specificity or selector change cannot silently invert it.
+    const platform = imports.indexOf(`${THEME_PACKAGE}/styles/design-platform.css`)
+    const scrollbar = imports.indexOf(`${THEME_PACKAGE}/styles/scrollbar.css`)
+    expect(platform).toBeGreaterThanOrEqual(0)
+    expect(scrollbar).toBeGreaterThan(platform)
+  })
+})