Merge remote-tracking branch 'origin/doc/host-client-group-readmes' into feat/directory-picker

# Conflicts:
#	packages/client/connection/src/client/fixture.ts
#	packages/client/connection/tests/fake-api.ts
#	packages/client/runtime/src/client/workspaces/service.ts
#	packages/client/runtime/tests/fake-api.ts
#	packages/client/ui-workspace/src/client/WorkspaceBrowser.tsx
#	packages/client/ui-workspace/src/client/WorkspacePicker.tsx
#	packages/client/ui-workspace/tests/workspace-picker.spec.tsx
#	packages/host/apiproxy/README.i18n.yaml
#	packages/host/apiproxy/src/api-proxy.ts
#	packages/host/apiproxy/src/api/host.schema.ts
#	packages/host/apiproxy/src/api/host.ts
#	packages/host/apiproxy/src/api/rpc-map.ts
#	packages/host/apiproxy/src/fetch/client.ts
#	packages/host/apiproxy/src/fetch/handler.ts
#	packages/host/apiproxy/tests/api-proxy-workspace.spec.ts
#	packages/host/apiproxy/tests/client-handler.spec.ts
#	packages/host/apiproxy/tests/fetch-carrier.spec.ts

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

@@ -1,3 +1,4 @@
+import { createUserMessage, createMessage, createToolResultMessage, CallId } from '@deepseek-ai/dsh-llm'
 // Minimal SessionEvent builders for orchestration tests (shape mirrors what the
 // host emits; only the fields the object layer reads).
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
@@ -13,7 +14,9 @@ export const ev = {
   turnStart: (seq: number, turn: number): SessionEvent =>
     at(seq, { type: 'turn/start', data: { turn, trigger: { kind: 'message', source: { kind: 'user' } } } }),
   user: (seq: number, body: string): SessionEvent =>
-    at(seq, { type: 'user/message', surfaceOp: 'append', data: { content: text(body), source: { kind: 'user' } } }),
+    at(seq, { type: 'user/message', surfaceOp: 'append', data: createUserMessage({
+      content: text(body), source: { kind: 'user' },
+    }) }),
   stepStart: (seq: number, turn: number, step = 0): SessionEvent =>
     at(seq, { type: 'step/start', data: { turn, step } }),
   chunkStart: (seq: number, turn: number, step = 0, index = 0): SessionEvent =>
@@ -21,11 +24,33 @@ export const ev = {
   chunkText: (seq: number, turn: number, piece: string, step = 0, index = 0): SessionEvent =>
     at(seq, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'text-delta', index, text: piece } } }),
   assistant: (seq: number, turn: number, body: string, step = 0): SessionEvent =>
-    at(seq, { type: 'assistant/message', surfaceOp: 'append', data: { turn, step, content: text(body), provenance: { provider: 'fake', model: 'fk-1' } } }),
+    at(seq, { type: 'assistant/message', surfaceOp: 'append', data: {
+      turn, step,
+      message: createMessage({
+        role: 'assistant',
+        content: text(body),
+        source: {
+          kind: 'model',
+          ...{ provider: 'fake', model: 'fk-1' },
+        },
+      }),
+    } }),
   toolCall: (seq: number, turn: number, callId: string, name: string, args: string, step = 0): SessionEvent =>
     at(seq, { type: 'tool/call', data: { turn, step, callId, name, arguments: args } }),
   toolResult: (seq: number, turn: number, callId: string, body: string, step = 0): SessionEvent =>
-    at(seq, { type: 'tool/result', surfaceOp: 'append', data: { turn, step, callId, content: text(body), isError: false } }),
+    at(seq, {
+      type: 'tool/result',
+      surfaceOp: 'append',
+      data: {
+        turn,
+        step,
+        message: createToolResultMessage({
+          callId: CallId(callId),
+          content: text(body),
+          isError: false,
+        }),
+      },
+    }),
   codeDispatchStart: (seq: number, parentCallId: string, n: number, name: string, args: unknown): SessionEvent =>
     at(seq, {
       type: 'tool/code-dispatch-start',
@@ -40,8 +65,10 @@ 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. */

packages/client/runtime/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 {
-  ClientResponse, CommandDescriptor, CommandExecuteResult, HostFrame, IApiClient, ModelTarget, MuxFrame,
+  ClientResponse, CommandDescriptor, HostFrame, IApiClient, ModelTarget, MuxFrame,
   RpcError, RpcReceipt, RpcRequest, RpcResponse, SessionId, SessionModels, SkillEntry,
   WorkspaceId, WorkspaceView,
 } from '@deepseek-ai/dsh-client-connection/client'
@@ -63,7 +64,7 @@ export class FakeApiClient implements IApiClient {
   onCreate: (payload: unknown) => Promise<RpcResponse<{ sessionId: SessionId }>> = () => Promise.resolve(ok({ sessionId: 'fk-new' as SessionId }))
   readonly defaultModel: ModelTarget = { provider: 'deepseek', model: 'deepseek-v4-flash' }
   onHistory: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number })
-  => Promise<RpcResponse<{ events: never[]; hasMore: boolean; todos?: { content: string; status: 'pending' | 'in_progress' | 'completed' }[] }>> =
+  => Promise<RpcResponse<{ events: never[]; hasMore: boolean }>> =
     () => Promise.resolve(ok({ events: [], hasMore: false }))
 
   onModels: (payload: unknown) => Promise<RpcResponse<SessionModels>> = () => Promise.resolve(ok({
@@ -84,6 +85,8 @@ export class FakeApiClient implements IApiClient {
     () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0, directoryPicker: 'browse' as const }))
   onPickDirectory: (payload: unknown) => Promise<RpcResponse<{ path: string | null }>> =
     () => Promise.resolve(ok({ path: null }))
+  onOpenPath: (payload: unknown) => Promise<RpcResponse<{ opened: true }>> =
+    () => Promise.resolve(ok({ opened: true as const }))
 
   onListDirectory: (payload: unknown) => Promise<RpcResponse<{
     path: string
@@ -119,6 +122,7 @@ export class FakeApiClient implements IApiClient {
     pickDirectory: (payload: unknown) => this.record('host.pickDirectory', payload, this.onPickDirectory(payload)),
     listDirectory: (payload: unknown) => this.record('host.listDirectory', payload, this.onListDirectory(payload)),
     createDirectory: (payload: unknown) => this.record('host.createDirectory', payload, this.onCreateDirectory(payload)),
+    openPath: (payload: unknown) => this.record('host.openPath', payload, this.onOpenPath(payload)),
   }
 
   onWorkspaceList: (payload: unknown) => Promise<RpcResponse<{ items: never[] }>> = () => Promise.resolve(ok({ items: [] }))
@@ -146,10 +150,12 @@ 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)),

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

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

packages/client/runtime/tests/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')
   })
 })
 

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

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

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

@@ -5,6 +5,7 @@
  * pre-instantiation buffering, and snapshot reference stability.
  */
 import { describe, expect, it } from 'vitest'
+import { createUserMessage } from '@deepseek-ai/dsh-llm'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type { MuxFrame, RpcId, SessionId } from '@deepseek-ai/dsh-client-connection/client'
 import { Session } from '../src/client/sessions/session.ts'
@@ -19,8 +20,12 @@ const rid = (id: string): RpcId => id as RpcId
 /** session/queued frame with the wire-sourced rpcId key (the host prompt path). */
 function queuedFrame(body: string, rpcId: string, steering = false): MuxFrame {
   return {
-    type: 'session/queued', sessionId: SID, content: text(body),
-    source: { kind: 'user', rpcId: rid(rpcId) } as never,
+    type: 'session/queued',
+    sessionId: SID,
+    message: createUserMessage({
+      content: text(body),
+      source: { kind: 'user', rpcId: rid(rpcId) } as never,
+    }),
     steering,
   }
 }
@@ -40,9 +45,12 @@ describe('queue intake', () => {
   it('falls back to the envelope rpcId when the source carries none, and tags non-text blocks', () => {
     const session = makeSession()
     session.handleMuxEnvelope(rid('env-2'), {
-      type: 'session/queued', sessionId: SID,
-      content: [{ type: 'text', text: 'hi' }, { type: 'image', data: 'x' } as never],
-      source: { kind: 'plugin', plugin: 'loop' },
+      type: 'session/queued',
+      sessionId: SID,
+      message: createUserMessage({
+        content: [{ type: 'text', text: 'hi' }, { type: 'image', data: 'x' } as never],
+        source: { kind: 'plugin', plugin: 'loop' },
+      }),
       steering: false,
     })
     expect(session.getSnapshot().queue).toEqual([{ key: 'f:env-2', preview: 'hi [image]' }])
@@ -93,14 +101,26 @@ describe('queue retirement (host queuedMirror rules)', () => {
     const foreignSteering = {
       seq: 0, time: 1,
       type: 'steering/message', surfaceOp: 'append',
-      data: { turn: 0, content: text('loop'), source: { kind: 'plugin', plugin: 'loop' } },
+      data: {
+        turn: 0,
+        message: createUserMessage({
+          content: text('loop'),
+          source: { kind: 'plugin', plugin: 'loop' },
+        }),
+      },
     } as never
     session.handleMuxEnvelope(rid('e4'), { type: 'session/event', sessionId: SID, event: foreignSteering })
     expect(session.getSnapshot().queue).toHaveLength(2)
     const matchedSteering = {
       seq: 1, time: 2,
       type: 'steering/message', surfaceOp: 'append',
-      data: { turn: 0, content: text('插话'), source: { kind: 'user', rpcId: rid('p-2') } },
+      data: {
+        turn: 0,
+        message: createUserMessage({
+          content: text('插话'),
+          source: { kind: 'user', rpcId: rid('p-2') },
+        }),
+      },
     } as never
     session.handleMuxEnvelope(rid('e5'), { type: 'session/event', sessionId: SID, event: matchedSteering })
     expect(session.getSnapshot().queue.map(r => r.key)).toEqual(['p-1'])
@@ -154,7 +174,13 @@ describe('queue reconnect semantics', () => {
     const committed = {
       seq: 6, time: 2,
       type: 'steering/message', surfaceOp: 'append',
-      data: { turn: 1, content: text('重连插话'), source: { kind: 'user', rpcId: rid('p-steer') } },
+      data: {
+        turn: 1,
+        message: createUserMessage({
+          content: text('重连插话'),
+          source: { kind: 'user', rpcId: rid('p-steer') },
+        }),
+      },
     } as never
     session.handleMuxEnvelope(rid('e3'), { type: 'session/event', sessionId: SID, event: committed })
     expect(session.getSnapshot().queue).toEqual([])

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

@@ -22,9 +22,9 @@ function makeSession(api = new FakeApiClient()): { api: FakeApiClient; session:
   return { api, session: new Session(SID, api) }
 }
 
-function histResponse(events: SessionEvent[], hasMore = false, todos?: { content: string; status: 'pending' | 'in_progress' | 'completed' }[]) {
+function histResponse(events: SessionEvent[], hasMore = false) {
   // history now returns HistoryEntry[] ({event, view?}); these tests are view-less.
-  return Promise.resolve(ok({ events: entries(events) as never[], hasMore, ...todos === undefined ? {} : { todos } }))
+  return Promise.resolve(ok({ events: entries(events) as never[], hasMore }))
 }
 
 describe('open', () => {
@@ -104,6 +104,28 @@ describe('live event path', () => {
     expect(session.getSnapshot().nodes).toEqual(before.nodes)
   })
 
+  it('materializes a command node from live lifecycle frames and reproduces it from a history window', async () => {
+    // Live path: run mints an executing node, done settles it in the flow.
+    const { session } = await opened()
+    const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
+    feed(ev.commandRun(6, 'cmd-live', 'plan'))
+    let command = session.getSnapshot().nodes.at(-1)
+    expect(command).toMatchObject({ kind: 'command', name: 'plan', args: '', outcome: null })
+    feed(ev.commandDone(7, 'cmd-live', 'success', '已进入 plan mode'))
+    command = session.getSnapshot().nodes.at(-1)
+    expect(command).toMatchObject({ kind: 'command', seq: 6, outcome: { kind: 'success', text: '已进入 plan mode' } })
+
+    // Replay path (refresh): the same pair inside the history window folds identically.
+    const replayed = await opened([
+      ...plainTurn(0, 0, 'a', 'b'),
+      ev.commandRun(6, 'cmd-live', 'plan'),
+      ev.commandDone(7, 'cmd-live', 'success', '已进入 plan mode'),
+    ])
+    expect(replayed.session.getSnapshot().nodes.at(-1)).toMatchObject({
+      kind: 'command', seq: 6, name: 'plan', outcome: { kind: 'success', text: '已进入 plan mode' },
+    })
+  })
+
   it('accumulates chunks into partial, then finalize swaps partial out as the node lands', async () => {
     const { session } = await opened()
     const feed = (event: SessionEvent) => { session.handleMuxEnvelope('r' as never, { type: 'session/event', sessionId: SID, event }) }
@@ -158,42 +180,6 @@ 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')]
@@ -207,37 +193,6 @@ 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', () => {

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/' },
@@ -79,7 +79,8 @@ describe('scope tree', () => {
     expect(scopeOf(scoped as Context)).toBe('s1')
     expect(scopeOf(b.ctx)).toBeUndefined()
     const binding = b.svc.binding(sid('s1'))
-    expect(binding?.session).toBe(b.svc.provideInfo('s1')?.hooks['session'])
+    b.svc.open(sid('s1'))
+    expect(binding?.session).toBe(b.svc.currentProvideInfo.getSnapshot().hooks['session'])
     expect(b.svc.binding(sid('s1'))).toBe(binding)
     expect(binding?.ctx).toBe(scoped)
   })
@@ -183,24 +184,82 @@ describe('current selection (migrated from ui-layout, arbitrated into the list s
 })
 
 describe('cell (render-layer session kit)', () => {
-  it('resolves an identity-stable {sessionId, session} cell; unknown ids yield undefined', async () => {
+  it('resolves an identity-stable {sessionId, session} cell through the current projection', async () => {
     const b = bench()
     await feedList(b, [{ id: 's1' }])
-    const info = b.svc.provideInfo('s1')
-    expect(info).toBeDefined()
-    expect(info?.sessionId).toBe('s1')
+    b.svc.open(sid('s1'))
+    const info = b.svc.currentProvideInfo.getSnapshot()
+    expect(info.sessionId).toBe('s1')
     // The bundle carries bare observables; hook binding happens in React.
-    expect(info?.hooks['session']).toBe(b.svc.binding(sid('s1'))?.session)
-    expect(b.svc.provideInfo('s1')).toBe(info)
-    expect(b.svc.provideInfo('ghost')).toBeUndefined()
+    expect(info.hooks['session']).toBe(b.svc.binding(sid('s1'))?.session)
+    // Re-staging the same id republishes nothing: identity holds.
+    b.svc.open(sid('s1'))
+    expect(b.svc.currentProvideInfo.getSnapshot()).toBe(info)
   })
 
-  it('provideInfo()/binding() are pure resolution: no staging, no deferred sweep', async () => {
+  it('currentProvideInfo follows selection: absent projection ↔ definite bundle, notified on each move', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1' }, { id: 's2' }])
+    const absent = b.svc.currentProvideInfo.getSnapshot()
+    expect(absent.sessionId).toBeUndefined()
+    expect(Object.hasOwn(absent.hooks, 'session')).toBe(true)
+    const notified = vi.fn()
+    b.svc.currentProvideInfo.subscribe(notified)
+    b.svc.open(sid('s1'))
+    const s1Bundle = b.svc.currentProvideInfo.getSnapshot()
+    expect(s1Bundle.sessionId).toBe('s1')
+    expect(s1Bundle.hooks['session']).toBe(b.svc.binding(sid('s1'))?.session)
+    expect(notified).toHaveBeenCalledTimes(1)
+    b.svc.open(sid('s2'))
+    const s2Bundle = b.svc.currentProvideInfo.getSnapshot()
+    expect(s2Bundle.sessionId).toBe('s2')
+    expect(s2Bundle).not.toBe(s1Bundle)
+    expect(notified).toHaveBeenCalledTimes(2)
+    b.svc.clear()
+    await Promise.resolve() // clearSelection projects through the manager notifier
+    expect(b.svc.currentProvideInfo.getSnapshot().sessionId).toBeUndefined()
+  })
+
+  it('a provider roster change under a stable current id republishes the bundle', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1' }])
+    b.svc.open(sid('s1'))
+    const before = b.svc.currentProvideInfo.getSnapshot()
+    const notified = vi.fn()
+    b.svc.currentProvideInfo.subscribe(notified)
+    const source = { getSnapshot: () => 'live', subscribe: () => () => {} }
+    const dispose = b.svc.provide({
+      hooks: ['extra'],
+      props: ['marker'],
+      resolve: () => ({ hooks: { extra: source }, props: { marker: 7 } }),
+    })
+    const added = b.svc.currentProvideInfo.getSnapshot()
+    expect(added).not.toBe(before)
+    expect(added).toMatchObject({ sessionId: 's1', props: { marker: 7 } })
+    expect(added.hooks['extra']).toBe(source)
+    expect(notified).toHaveBeenCalledTimes(1)
+    dispose()
+    const removed = b.svc.currentProvideInfo.getSnapshot()
+    expect(removed).not.toBe(added)
+    expect(Object.hasOwn(removed.hooks, 'extra')).toBe(false)
+    expect(notified).toHaveBeenCalledTimes(2)
+  })
+
+  it('an unsubscribed currentProvideInfo listener stops receiving notifications', async () => {
+    const b = bench()
+    await feedList(b, [{ id: 's1' }])
+    const notified = vi.fn()
+    const off = b.svc.currentProvideInfo.subscribe(notified)
+    off()
+    b.svc.open(sid('s1'))
+    expect(notified).not.toHaveBeenCalled()
+  })
+
+  it('binding() is pure resolution: no staging, no deferred sweep', async () => {
     const b = bench()
     await feedList(b, [{ id: 's1' }, { id: 's2' }])
     b.svc.open(sid('s1')) // staged
-    b.svc.provideInfo('s2') // resolution only — must NOT move the stage
-    b.svc.binding(sid('s2'))
+    b.svc.binding(sid('s2')) // resolution only — must NOT move the stage
     await feedList(b, [{ id: 's2' }]) // s1 removed: still staged → deferred, scope survives
     expect(b.svc.scope(sid('s1'))).toBeDefined()
   })
@@ -211,7 +270,6 @@ describe('cell (render-layer session kit)', () => {
     const historyCalls = () => b.api.calls.filter(c => c.method === 'session.history')
     // Resolution is addressing, not staging: no window pull.
     b.svc.scope(sid('s1'))
-    b.svc.provideInfo('s1')
     b.svc.binding(sid('s1'))
     expect(historyCalls()).toHaveLength(0)
     b.svc.open(sid('s1'))

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

@@ -97,18 +97,13 @@ function fakeWorkspaces() {
   return { list: { getSnapshot: () => state, subscribe: () => () => undefined } }
 }
 
-/** Minimal sessions face for the host seam (list observable + provide bundle). */
+/** Minimal sessions face for the host seam (list observable + current provide projection). */
 function fakeSessions() {
   const state = { ids: [], byId: {}, current: undefined as string | undefined }
+  const absentInfo = { sessionId: undefined, hooks: { session: undefined }, props: {} }
   return {
     list: { getSnapshot: () => state, subscribe: () => () => undefined },
-    provideInfo: (id: string) => (id === 'known'
-      ? {
-        sessionId: id,
-        hooks: { session: { getSnapshot: () => undefined, subscribe: () => () => undefined } },
-        props: {},
-      }
-      : undefined),
+    currentProvideInfo: { getSnapshot: () => absentInfo, subscribe: () => () => undefined },
   }
 }
 
@@ -232,13 +227,11 @@ describe('host face', () => {
     expect(host.entriesOf('t.host')).toHaveLength(0)
   })
 
-  it('exposes sessions list/current/provideInfo (current riding the list snapshot)', async () => {
+  it('exposes the session list and the atomic current provide projection', async () => {
     const bench = await boot()
     const host = captureHost(bench)
     expect(host.sessions.list.getSnapshot()).toMatchObject({ ids: [] })
-    expect(host.sessions.current.getSnapshot()).toBeUndefined()
-    expect(host.sessions.provideInfo('known')).toMatchObject({ sessionId: 'known' })
-    expect(host.sessions.provideInfo('ghost')).toBeUndefined()
+    expect(host.sessions.provideInfo.getSnapshot()).toMatchObject({ sessionId: undefined })
   })
 
   it('exposes the independent Workspace list source', async () => {

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

@@ -268,6 +268,17 @@ describe('WorkspacesService', () => {
     await expect(workspaces.createDirectory('/home/u', 'fresh')).rejects.toMatchObject({ rpcError: { code: 'directory-exists' } })
   })
 
+  it('opens a filesystem path through the host without local state', async () => {
+    const ctx = new Context()
+    const api = new FakeApiClient()
+    const sessions = new SessionsService(ctx, api)
+    const workspaces = new WorkspacesService(ctx, api, sessions)
+    await expect(workspaces.openPath('/w/alpha/a.ts')).resolves.toBeUndefined()
+    expect(api.callsOf('host.openPath')).toEqual([{ path: '/w/alpha/a.ts' }])
+    api.onOpenPath = () => Promise.resolve(err({ code: 'internal', message: 'boom', details: {} }))
+    await expect(workspaces.openPath('/missing')).rejects.toThrow(/path open failed/)
+  })
+
   it('deletes a Workspace or preserves it when the Host rejects deletion', async () => {
     const ctx = new Context()
     const api = new FakeApiClient()