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/host/apiproxy/src/api/commands.schema.ts

@@ -4,10 +4,11 @@
  */
 
 import { z } from 'zod'
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type { RequestPayload, ResponseValue } from './rpc-map.ts'
 import type { Wire } from './rpc.schema.ts'
 import { sessionIdSchema } from './sessions.schema.ts'
-import type { CommandDescriptor, CommandExecuteResult } from './commands.ts'
+import type { CommandDescriptor } from './commands.ts'
 
 /** CommandDescriptor row of command.list. */
 export const commandDescriptorSchema = z.object({
@@ -32,14 +33,12 @@ export const commandExecuteRequestSchema = z.object({
   line: z.string(),
 }) satisfies z.ZodType<Wire<RequestPayload<'command.execute'>>>
 
-/** Detached command outcome (result slot of command.execute's value). */
-export const commandExecuteResultSchema = z.object({
-  kind: z.union([z.literal('success'), z.literal('error')]),
-  text: z.string().optional(),
-}) satisfies z.ZodType<Wire<CommandExecuteResult>>
+/** CommandId: one brand cast after shape validation (the only cast point in this domain). */
+export const commandIdSchema = z.string().min(1) as unknown as z.ZodType<CommandId>
 
-/** command.execute response value (matched=false carries no result). */
+/** command.execute response value: pure admission — outcomes ride the logged
+ * lifecycle events; commandId (present exactly when matched) correlates with them. */
 export const commandExecuteValueSchema = z.object({
   matched: z.boolean(),
-  result: commandExecuteResultSchema.optional(),
+  commandId: commandIdSchema.optional(),
 }) satisfies z.ZodType<Wire<ResponseValue<'command.execute'>>>

packages/host/apiproxy/src/api/commands.ts

@@ -5,6 +5,7 @@
  * together), so there is no agent-less surface on this wire.
  */
 
+import type { CommandId } from '@deepseek-ai/dsh-commands/brand'
 import type { SessionId } from '@deepseek-ai/dsh-session/types'
 import type { RpcRequest, RpcResponse } from './rpc.ts'
 
@@ -22,12 +23,6 @@ export interface CommandDescriptor {
   readonly input?: { readonly hint: string }
 }
 
-/** Detached command outcome rendered directly by the requesting client. */
-export interface CommandExecuteResult {
-  readonly kind: 'success' | 'error'
-  readonly text?: string
-}
-
 /** Command-domain unary methods (the map keys command.* of RpcMethodMap). */
 export interface CommandsApi {
   /**
@@ -38,11 +33,16 @@ export interface CommandsApi {
 
   /**
    * Parses and executes one slash-command line against the addressed agent
-   * without sending it to the model. matched=false when syntax or name does
-   * not resolve (the client falls back to its default sink). The signal rides
-   * beside the request, never on the wire: the fetch carrier's request signal
-   * cancels the running handler.
+   * without sending it to the model — pure admission semantics. matched=false
+   * when syntax or name does not resolve (the client falls back to its
+   * default sink). The handler's outcome does NOT ride the response: the host
+   * executor durably logs the lifecycle (`command/run`/`command/done`), which
+   * broadcasts on the mux stream and renders as a persistent flow node.
+   * `commandId` is present exactly when matched — the minted lifecycle
+   * pairing id, letting the issuing client correlate this acknowledgment
+   * with that flow node. The signal rides beside the request, never on the
+   * wire: the fetch carrier's request signal cancels the running handler.
    */
   execute(request: RpcRequest<{ sessionId: SessionId; line: string }>, signal: AbortSignal):
-  Promise<RpcResponse<{ matched: boolean; result?: CommandExecuteResult }>>
+  Promise<RpcResponse<{ matched: boolean; commandId?: CommandId }>>
 }

packages/host/apiproxy/src/api/events.schema.ts

@@ -23,11 +23,18 @@ export const askUserQuestionItemSchema = z.object({
   multiSelect: z.boolean().optional(),
 }) satisfies z.ZodType<Wire<AskUserQuestionItem>>
 
+/** Unified message envelope carried by transient queue frames. */
+const messageSchema = z.object({
+  id: z.string().min(1),
+  role: z.union([z.literal('system'), z.literal('user'), z.literal('assistant')]),
+  content: z.array(contentBlockSchema),
+  source: z.looseObject({ kind: z.string() }),
+})
+
 /** MuxFrame union (payload slot of a mux-stream ServerRequest). */
 export const muxFrameSchema = z.discriminatedUnion('type', [
   z.object({ type: z.literal('session/event'), sessionId: sessionIdSchema, event: sessionEventSchema, view: toolEventViewSchema.optional() }),
   z.object({ type: z.literal('session/subscribed'), sessionId: sessionIdSchema, lastSeq: z.number().int() }),
-  z.object({ type: z.literal('session/title'), sessionId: sessionIdSchema, title: z.string().min(1), eventSeq: z.number().int().nonnegative(), updatedAt: z.number() }),
   z.object({ type: z.literal('approval/requested'), sessionId: sessionIdSchema, approvalId: approvalRequestIdSchema, toolName: z.string(), callId: z.string().optional(), reason: z.string().optional() }),
   z.object({ type: z.literal('approval/resolved'), sessionId: sessionIdSchema, approvalId: approvalRequestIdSchema, outcome: z.union([z.literal('allowed-once'), z.literal('rejected'), z.literal('cancelled'), z.literal('unavailable')]) }),
   // Non-empty by wire contract: the user-interaction service rejects empty
@@ -35,8 +42,10 @@ export const muxFrameSchema = z.discriminatedUnion('type', [
   // and must fail loud here, not reach the composer.
   z.object({ type: z.literal('question/requested'), sessionId: sessionIdSchema, questions: z.array(askUserQuestionItemSchema).min(1) }),
   z.object({ type: z.literal('question/resolved'), sessionId: sessionIdSchema, questionRpcId: rpcIdSchema, outcome: z.union([z.literal('answered'), z.literal('cancelled')]) }),
-  // content/source reuse the wide passthroughs (both are merge-extensible in core).
-  z.object({ type: z.literal('session/queued'), sessionId: sessionIdSchema, content: z.array(contentBlockSchema), source: z.looseObject({ kind: z.string() }), steering: z.boolean() }),
+  z.object({ type: z.literal('session/queued'), sessionId: sessionIdSchema, message: messageSchema, steering: z.boolean() }),
+  // value stays wide: it already passed its unit's own schema on the host,
+  // and deep-validating here would import every domain's schema into the carrier.
+  z.object({ type: z.literal('session/projection'), sessionId: sessionIdSchema, key: z.string().min(1), value: z.unknown(), seq: z.number().int().nonnegative() }),
   z.object({ type: z.literal('stream/error'), error: rpcErrorSchema }),
 ]) as unknown as z.ZodType<MuxFrame>
 

packages/host/apiproxy/src/api/events.ts

@@ -8,7 +8,7 @@
 
 import type { AskUserQuestionItem } from '@deepseek-ai/dsh-user-interaction/types'
 import type { ApprovalOutcome, ApprovalRequestId } from '@deepseek-ai/dsh-user-approval/types'
-import type { ContentBlock, MessageSource } from '@deepseek-ai/dsh-llm/types'
+import type { Message } from '@deepseek-ai/dsh-llm/types'
 import type { CallId } from '@deepseek-ai/dsh-llm/brand'
 import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
 import type { ToolCallView, ToolResultView } from '@deepseek-ai/dsh-tools/presentation'
@@ -35,9 +35,9 @@ export type ToolEventView =
 export interface EventsApi {
   /**
    * All-session aggregated mux stream. On open, emits a subscribed control frame for every
-   * attached session followed by its optional latest title snapshot, then replays each
-   * session's still-pending approval/question requested frames (rpcId reused verbatim — the
-   * refresh-recovery baseline).
+   * attached session, then replays each session's still-pending approval/question requested
+   * frames (rpcId reused verbatim — the refresh-recovery baseline). Session titles ride the
+   * generic projection pair (history-tail projections block + session/projection frames).
    * since: resume seam, unimplemented in v1 (ignored if passed); reconnection = reopen the
    * stream + refetch history.
    */
@@ -57,7 +57,6 @@ export interface EventsApi {
 export type MuxFrame =
   | { type: 'session/event'; sessionId: SessionId; event: SessionEvent; view?: ToolEventView }
   | { type: 'session/subscribed'; sessionId: SessionId; lastSeq: number }
-  | { type: 'session/title'; sessionId: SessionId; title: string; eventSeq: number; updatedAt: number }
   | { type: 'approval/requested'; sessionId: SessionId; approvalId: ApprovalRequestId; toolName: string; callId?: CallId; reason?: string }
   | { type: 'approval/resolved'; sessionId: SessionId; approvalId: ApprovalRequestId; outcome: ApprovalOutcome }
   | { type: 'question/requested'; sessionId: SessionId; questions: AskUserQuestionItem[] }
@@ -70,11 +69,20 @@ export type MuxFrame =
    * refresh-recovery baseline as pending questions); queue clearing on cancel
    * has no dedicated frame — clients fold it from the status flip.
    * `steering` is the host's acceptance-time queue classification and remains
-   * authoritative in reconnect snapshots. `source` carries the prompt's rpcId
+   * authoritative in reconnect snapshots. `message.source` carries the prompt's rpcId
    * when the message came over this wire (the client's provisional-echo
    * reconciliation key).
    */
-  | { type: 'session/queued'; sessionId: SessionId; content: ContentBlock[]; source: MessageSource; steering: boolean }
+  | { type: 'session/queued'; sessionId: SessionId; message: Message; steering: boolean }
+  /**
+   * One projection unit's finished value changed (session-projection RFC).
+   * Live push state, never logged — replay recomputes on the host (the
+   * tool-view posture). `value` is the unit's schema-validated view output;
+   * `seq` is the unit's watermark at emission. Clients keep one generic
+   * per-session value store under higher-seq-wins, seeded by the history
+   * tail page's projections block.
+   */
+  | { type: 'session/projection'; sessionId: SessionId; key: string; value: unknown; seq: number }
   | { type: 'stream/error'; error: RpcError }
 
 /**

packages/host/apiproxy/src/api/host.schema.ts

@@ -64,3 +64,12 @@ export const hostCreateDirectoryRequestSchema = z.object({
 export const hostCreateDirectoryValueSchema = z.object({
   path: z.string(),
 }) satisfies z.ZodType<Wire<ResponseValue<'host.createDirectory'>>>
+/** host.openPath request payload. */
+export const hostOpenPathRequestSchema = z.object({
+  path: z.string().min(1),
+}) satisfies z.ZodType<Wire<RequestPayload<'host.openPath'>>>
+
+/** host.openPath response value. */
+export const hostOpenPathValueSchema = z.object({
+  opened: z.literal(true),
+}) satisfies z.ZodType<Wire<ResponseValue<'host.openPath'>>>

packages/host/apiproxy/src/api/host.ts

@@ -89,4 +89,15 @@ export interface HostApi {
   createDirectory(
     request: RpcRequest<{ path: string; name: string }>,
   ): Promise<RpcResponse<{ path: string }>>
+
+  /**
+   * Open a filesystem path with the operating system's default application
+   * (Finder / Explorer / xdg-open hand-off). The browser carrier's
+   * prefix-wide trust fence covers this privileged method like every other
+   * `/api` request.
+   */
+  openPath(
+    request: RpcRequest<{ path: string }>,
+    signal: AbortSignal,
+  ): Promise<RpcResponse<{ opened: true }>>
 }

packages/host/apiproxy/src/api/index.ts

@@ -27,11 +27,11 @@ export interface ApiProxy {
 // ---- Domain interfaces and payload entities ----
 export type {
   HistoryEntry, ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
-  ModelReasoningEffort, ModelTarget, SessionModels, SessionsApi, SessionSummary,
+  ModelReasoningEffort, ModelTarget, SessionModels, SessionProjectionsBlock, SessionsApi, SessionSummary,
 } from './sessions.ts'
 export type { DirectoryEntry, DirectoryListing, DirectoryPickerKind, HostApi } from './host.ts'
 export type { WorkspaceApi, WorkspaceId, WorkspaceView } from './workspace.ts'
-export type { CommandsApi, CommandDescriptor, CommandExecuteResult } from './commands.ts'
+export type { CommandsApi, CommandDescriptor } from './commands.ts'
 export type { SkillsApi, SkillEntry } from './skills.ts'
 export type { EventsApi, MuxFrame, HostFrame, ToolCallView, ToolEventView, ToolResultView } from './events.ts'
 export type { ApprovalResponsePayload } from './approvals.ts'

packages/host/apiproxy/src/api/rpc-map.ts

@@ -28,6 +28,7 @@ export interface RpcMethodMap {
   'host.pickDirectory': HostApi['pickDirectory']
   'host.listDirectory': HostApi['listDirectory']
   'host.createDirectory': HostApi['createDirectory']
+  'host.openPath': HostApi['openPath']
   'workspace.list': WorkspaceApi['list']
   'workspace.create': WorkspaceApi['create']
   'workspace.rename': WorkspaceApi['rename']

packages/host/apiproxy/src/api/sessions.schema.ts

@@ -11,7 +11,7 @@ import type { RequestPayload, ResponseValue } from './rpc-map.ts'
 import type { Wire } from './rpc.schema.ts'
 import type {
   HistoryEntry, ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
-  ModelReasoningEffort, ModelTarget, SessionSummary,
+  ModelReasoningEffort, ModelTarget, SessionProjectionsBlock, SessionSummary,
 } from './sessions.ts'
 import type { ToolEventView } from './events.ts'
 import type { WorkspaceId } from './workspace.ts'
@@ -139,17 +139,22 @@ export const historyEntrySchema = z.object({
   view: toolEventViewSchema.optional(),
 }) satisfies z.ZodType<Wire<HistoryEntry>>
 
-/** One todo item of the tail page's session-level projection (the todo/write payload shape). */
-export const todoItemSchema = z.object({
-  content: z.string(),
-  status: z.union([z.literal('pending'), z.literal('in_progress'), z.literal('completed')]),
-})
+/**
+ * Projection baseline passthrough: `values` stays a wide record — each value
+ * was already parsed by its provider's own schema on the host side, and
+ * deep-validating here would import every domain's schema into the carrier.
+ */
+export const sessionProjectionsBlockSchema = z.object({
+  // -1 = empty log (the lastSeq convention of session/subscribed).
+  asOfSeq: z.number().int().min(-1),
+  values: z.record(z.string(), z.unknown()),
+}) as unknown as z.ZodType<SessionProjectionsBlock>
 
-/** session.history response value. */
+/** session.history response value (projections rides the tail page only). */
 export const sessionHistoryValueSchema = z.object({
   events: z.array(historyEntrySchema),
   hasMore: z.boolean(),
-  todos: z.array(todoItemSchema).optional(),
+  projections: sessionProjectionsBlockSchema.optional(),
 }) satisfies z.ZodType<Wire<ResponseValue<'session.history'>>>
 
 /** session.models request payload. */

packages/host/apiproxy/src/api/sessions.ts

@@ -5,7 +5,10 @@
  */
 
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
-import type { SessionEvent, SessionId, TodoItem } from '@deepseek-ai/dsh-session/types'
+import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
+// The pure-type outlet: api/ is browser-importable, and the package root's
+// cordis Context merge (via dsh-agent) must not enter client aggregates.
+import type { SessionProjectionMap } from '@deepseek-ai/dsh-session-projection/types'
 import type { RpcId, RpcRequest, RpcResponse } from './rpc.ts'
 import type { ToolEventView } from './events.ts'
 import type { WorkspaceId } from './workspace.ts'
@@ -32,6 +35,23 @@ export interface HistoryEntry {
   view?: ToolEventView
 }
 
+/**
+ * The projection baseline riding the history tail page: one synchronous cut
+ * over every registered projection unit, read from the registry's watermark
+ * cache. `asOfSeq` is the seq of the last committed event every value
+ * reflects — the window tail event seq (`-1` for an empty log, mirroring
+ * `session/subscribed.lastSeq`), directly comparable with
+ * `session/projection` frame seqs under the client's higher-seq-wins rule. A
+ * key absent from `values` means the capability is absent (its domain plugin
+ * is unmounted).
+ */
+export interface SessionProjectionsBlock {
+  /** Seq of the last event the values reflect; -1 for an empty log. */
+  asOfSeq: number
+  /** Whole current value per registered projection key. */
+  values: Partial<SessionProjectionMap>
+}
+
 /** Complete model target selected for one session. */
 export interface ModelTarget {
   /** Registered provider route. */
@@ -149,13 +169,14 @@ export interface SessionsApi {
    * Each entry pairs the raw SessionEvent with the host-computed view (tool events whose
    * presenter produced one, evaluated against the registry at pagination time); the client
    * rebuilds the surface from the events with the shared fold.
-   * The tail page (beforeSeq absent) also carries `todos` — the session's current todo
-   * projection (latest `todo/write` over the FULL log, independent of the page window) —
-   * so a paged client restores the plan without walking history; absent when the session
-   * never wrote one. Older pages omit it (the projection is session-level, not per-page).
+   * The tail page — and only the tail page — additionally carries `projections`
+   * when the deployment mounts the session-projection registry: every moment
+   * the client needs a fresh baseline already pulls the tail page, and
+   * loadOlder (the only beforeSeq path) is the only path that never needs one.
+   * A deployment without the registry serves histories without the block.
    */
   history(request: RpcRequest<{ sessionId: SessionId; beforeSeq?: number; maxMessages?: number }>):
-  Promise<RpcResponse<{ events: HistoryEntry[]; hasMore: boolean; todos?: TodoItem[] }>>
+  Promise<RpcResponse<{ events: HistoryEntry[]; hasMore: boolean; projections?: SessionProjectionsBlock }>>
 
   /** Reads a fresh advisory model directory for this session. Provider lookups run independently. */
   models(request: RpcRequest<{ sessionId: SessionId }>): Promise<RpcResponse<SessionModels>>