Merge remote-tracking branch 'origin/master' into codex/basic-session-search

# Conflicts:
#	apps/web/tests/snapshots/question-composer/answered.expected.md
#	packages/client/connection/tests/fake-api.ts
#	packages/client/runtime/README.i18n.yaml
#	packages/client/runtime/tests/fake-api.ts
#	packages/client/ui-workspace/README.i18n.yaml
#	packages/client/ui-workspace/README.md
#	packages/client/ui-workspace/README.zh.md
#	packages/client/ui-workspace/src/client/WorkspaceBrowser.tsx
#	packages/client/ui-workspace/tests/apply.spec.ts
#	packages/host/apiproxy/README.i18n.yaml
#	packages/host/apiproxy/README.md
#	packages/host/apiproxy/README.zh.md
#	packages/host/apiproxy/src/api-proxy.ts
#	packages/host/apiproxy/src/api/index.ts
#	packages/host/apiproxy/src/api/sessions.schema.ts
#	packages/host/apiproxy/src/fetch/client.ts
#	packages/host/apiproxy/src/fetch/handler.ts
#	packages/host/apiproxy/tests/fetch-carrier.spec.ts
#	packages/host/apiproxy/tests/rpc-schemas.spec.ts
#	packages/session-query/session-query/tests/search-helpers.spec.ts

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

@@ -2,8 +2,8 @@
 // data source on a real clock; behavior tests need per-case responses and
 // deferred-controlled timing). Streams are hand pumps: pushMux/pushHost.
 import type {
-  ClientResponse, CommandDescriptor, CommandExecuteResult, HostFrame, IApiClient, MuxFrame,
-  RpcError, RpcReceipt, RpcRequest, RpcResponse, SessionId, SessionSearchItem, SkillEntry,
+  ClientResponse, CommandDescriptor, CommandExecuteResult, HostFrame, IApiClient, ModelTarget, MuxFrame,
+  RpcError, RpcReceipt, RpcRequest, RpcResponse, SessionId, SessionModels, SessionSearchItem, SkillEntry,
   WorkspaceId, WorkspaceView,
 } from '@deepseek-ai/dsh-client-connection/client'
 import { RpcId } from '@deepseek-ai/dsh-client-connection/client'
@@ -63,14 +63,29 @@ export class FakeApiClient implements IApiClient {
   onSearch: (payload: unknown) => Promise<RpcResponse<{ items: SessionSearchItem[]; hasMore: boolean }>> =
     () => Promise.resolve(ok({ items: [], hasMore: false }))
   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.resolve(ok({ events: [], hasMore: false }))
 
+  onModels: (payload: unknown) => Promise<RpcResponse<SessionModels>> = () => Promise.resolve(ok({
+    current: this.defaultModel,
+    groups: [{
+      id: 'deepseek',
+      name: 'DeepSeek',
+      models: [{ id: 'deepseek-v4-flash', name: 'DeepSeek V4 Flash' }],
+    }],
+    failures: [],
+  }))
+  onSelectModel: (payload: { provider: string; model: string }) =>
+  Promise<RpcResponse<{ selected: ModelTarget }>> =
+    payload => Promise.resolve(ok({ selected: { provider: payload.provider, model: payload.model } }))
   onPrompt: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
   onCancel: (payload: unknown) => Promise<RpcResponse<{ accepted: true }>> = () => Promise.resolve(ok({ accepted: true as const }))
   onDescribe: (payload: unknown) => Promise<RpcResponse<{ version: string; cwd: string; attachedSessions: number }>> =
     () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0 }))
+  onPickDirectory: (payload: unknown) => Promise<RpcResponse<{ path: string | null }>> =
+    () => Promise.resolve(ok({ path: null }))
 
   private readonly muxConns: StreamConn<MuxFrame>[] = []
   private readonly hostConns: StreamConn<HostFrame>[] = []
@@ -88,12 +103,16 @@ export class FakeApiClient implements IApiClient {
     create: (payload: unknown) => this.record('session.create', payload, this.onCreate(payload)),
     history: (payload: { sessionId: SessionId; beforeSeq?: number; maxMessages?: number }) =>
       this.record('session.history', payload, this.onHistory(payload)),
+    models: (payload: unknown) => this.record('session.models', payload, this.onModels(payload)),
+    selectModel: (payload: { provider: string; model: string }) =>
+      this.record('session.selectModel', payload, this.onSelectModel(payload)),
     prompt: (payload: unknown) => this.record('session.prompt', payload, this.onPrompt(payload)),
     cancel: (payload: unknown) => this.record('session.cancel', payload, this.onCancel(payload)),
   }
 
   readonly host: IApiClient['host'] = {
     describe: (payload: unknown) => this.record('host.describe', payload, this.onDescribe(payload)),
+    pickDirectory: (payload: unknown) => this.record('host.pickDirectory', payload, this.onPickDirectory(payload)),
   }
 
   onWorkspaceList: (payload: unknown) => Promise<RpcResponse<{ items: never[] }>> = () => Promise.resolve(ok({ items: [] }))
@@ -121,12 +140,10 @@ 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; result?: CommandExecuteResult }>> =
+    () => 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)),