feat(host,client): compose directory picking through slots — dual-face -native, no wire advertisement

ui-workspace's two trigger surfaces each declare a single-kind directory-flow hole (conversation.hero.workspace.directoryFlow / sidebar.workspaces.directoryFlow, same owner contract) and keep only the trigger and the adoption: the Open-local- folder entry renders while the surface's hole is occupied, and the occupant reports one picked path per open through the hole's owner conversation (open/busy/onPicked/onCancel/onError). directory-picker-native becomes dual-face: its browser half fills both holes with a renderless occupant driving host.pickDirectory, so the cordis.yml row that mounts the backend also composes the client interaction — a mismatch is impossible and a second flow package fails at client load. With composition wiring both sides, the host.describe.directoryPicker advertisement and the client's kind branching lose their last consumer: the field, WorkspacesService.directoryPickerKind(), the DirectoryPickerKind wire type, and the picker's per-open describe read are deleted. The connection fixture now serves a deterministic pickDirectory path so the keyless snapshot drives the full pick-then-adopt flow. ui-workspace's hand-rolled declaration deferral is replaced by the deferRegistration helper it duplicated.
2026-07-28 21:51:01 +08:00
parent 51402ac7af
commit 85ca8be104
59 changed files with 614 additions and 385 deletions
@@ -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 .agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md
-2026-07-28-directory-picker-capability-seam.md: 78ae05e0da67bff791c0b4f315451aa02e1fa6f4
-2026-07-28-directory-picker-capability-seam.zh.md: bd527e2a1dba6934300a50877d4777f7f9fa24b1
+2026-07-28-directory-picker-capability-seam.md: ce5a2695345e29db5739df206965720559783ce3
+2026-07-28-directory-picker-capability-seam.zh.md: 5b73c3c48493d4f178a523db19bc124eda9c7cca
@@ -10,7 +10,9 @@ The web GUI's "Open local folder" flow was hardwired to one interaction: `host.p

 ## Decision

-A three-package capability seam in `packages/host/` — `directory-picker` (interface), `directory-picker-native`, `directory-picker-browse` (backends) — with one contract method: `capability()` returns a **discriminated union**, `{ kind: 'native', pick(signal) }` or `{ kind: 'browse', list(path?), createDirectory(path, name) }`. The gateway (`dsh-host-apiproxy`) injects `directoryPicker`, advertises the kind through `host.describe.directoryPicker`, serves the matching RPCs, and answers `directory-picker-unavailable` for the other kind; the client branches on the advertised kind and hides the affordance for unknown kinds (merge-extensible default). Composition (`cordis.yml`) is the swap point; the union is discriminated because the backends differ in *interaction shape* — flattening them into one method set would force every backend to fake the other's shape.
+A three-package capability seam in `packages/host/` — `directory-picker` (interface), `directory-picker-native`, `directory-picker-browse` (backends) — with one contract method: `capability()` returns a **discriminated union**, `{ kind: 'native', pick(signal) }` or `{ kind: 'browse', list(path?), createDirectory(path, name) }`. The gateway (`dsh-host-apiproxy`) injects `directoryPicker`, serves the matching RPCs, and answers `directory-picker-unavailable` for the other kind. The union is discriminated because the backends differ in *interaction shape* — flattening them into one method set would force every backend to fake the other's shape.
+
+**The client side is slot-composed, not advertisement-branched.** ui-workspace's two trigger surfaces each declare a `single` directory-flow hole (`conversation.hero.workspace.directoryFlow` / `sidebar.workspaces.directoryFlow`; two keys because a hole has exactly one declaring slot entry — same owner contract, same occupant). Each backend package is **dual-face**: its browser half registers the matching interaction into both holes — `-native` a renderless occupant driving `host.pickDirectory`, `-browse` the in-app browsing dialog. The hole's owner conversation (`open`/`busy`/`onPicked`/`onCancel`/`onError`) carries the whole exchange: ui-workspace keeps the trigger (menu entry rendered only while the hole is occupied) and the adoption (`createWorkspace({path})`, conflict/error dialog, Choose again), the occupant owns everything between `open` and the picked path. One `cordis.yml` row therefore swaps the host capability and the client flow together; a mismatch is impossible by construction, and mounting two flow packages fails at client load (`single` hole). The earlier `host.describe.directoryPicker` advertisement and the client's kind branching are deleted — with composition wiring both sides, a wire fact for the client to branch on had no remaining consumer. The hole registry (`ctx.slots.entries`) replaces it as the per-menu-open occupancy read.

 Placement and policy rulings folded into this decision:

@@ -30,7 +32,7 @@ Placement and policy rulings folded into this decision:

 ## Consequences

- `cordis.yml` chooses the interaction; `apps/cli` currently mounts `-native` (unchanged behavior). The GUI already gates its picking affordance on `describe.directoryPicker` (non-`native` kinds hide it); the in-app browser PR flips the default to `-browse` and adds the browse UI.
- The wire gains `host.listDirectory`/`host.createDirectory`, four error codes, and the `describe.directoryPicker` field; the connection fixture serves a deterministic browse tree for keyless assembled tests.
- A future interaction (or an Electron provider of the `native` interaction) is one backend package plus a client branch — no gateway surgery.
+- `cordis.yml` chooses the interaction; `apps/cli` currently mounts `-native` (unchanged behavior). The in-app browser PR flips that one row to `-browse`, swapping backend and UI together.
+- The wire gains `host.listDirectory`/`host.createDirectory` and four error codes; the connection fixture serves a deterministic browse tree and a deterministic `pickDirectory` path for keyless assembled tests.
+- A future interaction (or an Electron provider of the `native` interaction) is one dual-face backend package — no gateway surgery, no ui-workspace edits.
 - `ApiProxyDefaults.pickDirectory` (test-only injection) is gone; tests provide a stub `ctx.directoryPicker` like any other service.
@@ -10,7 +10,9 @@ web GUI 的"打开本地文件夹"流程被焊死在一种交互上：`host.pick

 ## 决策

-在 `packages/host/` 落一个三包能力 seam——`directory-picker`（接口）、`directory-picker-native`、`directory-picker-browse`（后端）——唯一契约方法 `capability()` 返回**可辨识联合**：`{ kind: 'native', pick(signal) }` 或 `{ kind: 'browse', list(path?), createDirectory(path, name) }`。网关（`dsh-host-apiproxy`）注入 `directoryPicker`，经 `host.describe.directoryPicker` 广播 kind，提供对应的 RPC，另一种 kind 的调用以 `directory-picker-unavailable` 应答；客户端按广播的 kind 分支，未知 kind 隐藏入口（可合并扩展的默认分支）。组合（`cordis.yml`）就是换装点；联合之所以可辨识，是因为后端差异在**交互形态**——压平成统一方法集会逼每个后端伪装另一方的形态。
+在 `packages/host/` 落一个三包能力 seam——`directory-picker`（接口）、`directory-picker-native`、`directory-picker-browse`（后端）——唯一契约方法 `capability()` 返回**可辨识联合**：`{ kind: 'native', pick(signal) }` 或 `{ kind: 'browse', list(path?), createDirectory(path, name) }`。网关（`dsh-host-apiproxy`）注入 `directoryPicker`，提供对应的 RPC，另一种 kind 的调用以 `directory-picker-unavailable` 应答。联合之所以可辨识，是因为后端差异在**交互形态**——压平成统一方法集会逼每个后端伪装另一方的形态。
+
+**client 侧靠 slot 组合，而非按广播分支。** ui-workspace 的两个触发表层各自声明一个 `single` 目录流洞（`conversation.hero.workspace.directoryFlow`／`sidebar.workspaces.directoryFlow`；之所以是两个 key，是因为一个洞只有一个声明它的 slot entry——owner 契约相同、占用者相同）。每个后端包都是**双面包**：其 browser half 把匹配的交互注册进两个洞——`-native` 是驱动 `host.pickDirectory` 的无渲染占用者，`-browse` 是应用内浏览对话框。洞的 owner 会话（`open`/`busy`/`onPicked`/`onCancel`/`onError`）承载整个交换：ui-workspace 保留触发（菜单入口仅在洞被占用时渲染）与接纳（`createWorkspace({path})`、冲突／错误对话框、重新选择），占用者持有从 `open` 到所选路径之间的一切。因此一行 `cordis.yml` 同时切换宿主能力与 client 流程；错配在构造上不可能，同时挂两个流程包会在 client 加载期失败（`single` 洞）。早先的 `host.describe.directoryPicker` 广播与客户端 kind 分支被删除——组合已经接好两侧后，供客户端分支用的 wire 事实不再有任何消费者。洞注册表（`ctx.slots.entries`）取而代之，成为每次打开菜单的占用读取。

 并入本决策的位置与策略裁决：

@@ -30,7 +32,7 @@ web GUI 的"打开本地文件夹"流程被焊死在一种交互上：`host.pick

 ## 后果

- `cordis.yml` 决定交互形态；`apps/cli` 当前挂 `-native`（行为不变）。GUI 已按 `describe.directoryPicker` 门控其选目录入口（非 `native` kind 一律隐藏）；应用内浏览器 PR 将把默认翻到 `-browse` 并补上浏览 UI。
- 协议新增 `host.listDirectory`／`host.createDirectory`、四个错误码与 `describe.directoryPicker` 字段；connection fixture 提供确定性浏览树供无密钥组装测试使用。
- 未来的新交互（或提供 `native` 交互的 Electron 实现）只是一个后端包加一个客户端分支——无需网关手术。
+- `cordis.yml` 决定交互形态；`apps/cli` 当前挂 `-native`（行为不变）。应用内浏览器 PR 只翻这一行到 `-browse`，后端与 UI 同时切换。
+- 协议新增 `host.listDirectory`／`host.createDirectory` 与四个错误码；connection fixture 提供确定性浏览树与确定性 `pickDirectory` 路径供无密钥组装测试使用。
+- 未来的新交互（或提供 `native` 交互的 Electron 实现）只是一个双面后端包——无需网关手术，也不动 ui-workspace。
 - `ApiProxyDefaults.pickDirectory`（仅测试注入）删除；测试像提供其他服务一样提供 stub `ctx.directoryPicker`。
@@ -240,8 +240,10 @@
 # The API gateway: the transport-agnostic dispatch face every client shape
 # shares. provider/model are the host default routing — the profile json's
 # mapping target (user config overrides these engineering defaults).
-# Directory-picking backend consumed by the gateway's host.* picker RPCs.
-# Swap point: mount '-browse' instead for the in-app browser (remote-capable).
+# Directory-picking package, dual-face: the node half serves the gateway's
+# host.* picker RPCs, the browser half fills ui-workspace's directory-flow
+# slots — one row composes the whole interaction. Swap point: mount
+# '-browse' instead for the in-app browser (remote-capable).
 - id: directory-picker
  name: '@deepseek-ai/dsh-host-directory-picker-native'

@@ -37,6 +37,15 @@ const PLUGINS: readonly (WebBootEntry & { dir: string })[] = [
    ],
  },
  { id: '@deepseek-ai/dsh-client-ui-trajectory', dir: 'ui-trajectory', url: '/plugins/ui-trajectory.js', rev: 'fx', inject: ['@deepseek-ai/dsh-client-ui-conversation'] },
+  // Dual-face host package: its browser half fills the directory-flow holes
+  // (the same composition row apps/cli mounts for the node-side backend).
+  {
+    id: '@deepseek-ai/dsh-host-directory-picker-native',
+    dir: '../host/directory-picker-native',
+    url: '/plugins/directory-picker-native.js',
+    rev: 'fx',
+    inject: ['@deepseek-ai/dsh-client-runtime', '@deepseek-ai/dsh-client-ui-workspace'],
+  },
 ]

 const bundles = new Map(PLUGINS.map(plugin => [
@@ -174,18 +183,24 @@ it('locks the composer in the New Session view state until a Workspace is chosen
  `)
 })

-it('hides the Open-local-folder entry under the fixture host\'s browse picker capability', async () => {
+it('adopts a directory through the composed native flow and lands in its blank session', async () => {
  boot('?fixture=empty')

  await findLockedComposer()
  fireEvent.click(workspaceChip())
  const menu = await screen.findByRole('menu')
-  // Flush the advertised-kind read (fixture describe resolves in microtasks):
-  // the fixture serves `browse`, whose in-app UI is not wired yet, so the
-  // dialog affordance must not render — only the create action remains.
-  await act(async () => {})
+  // The composed flow package occupies the directory-flow hole, so the
+  // picking affordance is present (no advertised-kind read exists anymore).
  expect(within(menu).getAllByRole('menuitem').map(item => visibleText(item)))
-    .toEqual(['Create a new workspace'])
+    .toEqual(['Open local folder…', 'Create a new workspace'])
+  fireEvent.click(within(menu).getByRole('menuitem', { name: 'Open local folder…' }))
+  // The renderless native flow drives the fixture's deterministic pick and
+  // the owner adopts the returned path into a real Workspace.
+  await act(async () => {})
+  await findHeroComposer()
+  await waitFor(() => {
+    expect(visibleText(screen.getByRole('tree', { name: 'Sessions' }))).toContain('project')
+  })
 })

 it('selects the recent Workspace and opens its blank Session on first load', async () => {
@@ -364,7 +364,7 @@ flowchart LR
 | `ctx.tasks` | `seam` | [`tasks`](../packages/tasks/tasks) | [`tasks-local`](../packages/tasks/tasks-local) | [`tool-bash`](../packages/bash/tool-bash), [`tool-pty`](../packages/pty/tool-pty), [`tool-subagent`](../packages/subagent/tool-subagent), [`tool-tasks`](../packages/tasks/tool-tasks) | - | Producers (background bash, PTY sends, and subagent delegations) register running work; tool-tasks is the model-facing control surface that reads, lists, and kills it; tasks-local is the process-local registry. |
 | `ctx.web` | `seam` | [`web`](../packages/web/web) | [`web-search-exa`](../packages/web/web-search-exa), [`web-search-perplexity`](../packages/web/web-search-perplexity), [`web-search-deepseek`](../packages/web/web-search-deepseek), [`web-fetch-local`](../packages/web/web-fetch-local) | [`tool-web`](../packages/web/tool-web) | - | Search and fetch providers register into one ctx.web seam; tool-web owns the stable model-facing names. |
 | `ctx.spillStore` | `seam` | [`spill`](../packages/spill/spill) | [`spill-local`](../packages/spill/spill-local) | [`spill-policy`](../packages/spill/spill-policy) | - | The backend saves oversized tool text and returns a model-facing locator plus retrieval hint; spill-policy is the tools/post-execute consumer that decides when to spill. |
-| `ctx.directoryPicker` | `seam` | `directory-picker` | `directory-picker-native`, `directory-picker-browse` | `apiproxy` | - | Discriminated interaction capability: the native backend opens one OS chooser on the host display, the browse backend serves listing/creation primitives for the in-app browser; the gateway advertises the kind via host.describe. |
+| `ctx.directoryPicker` | `seam` | `directory-picker` | `directory-picker-native`, `directory-picker-browse` | `apiproxy` | - | Discriminated interaction capability: the native backend opens one OS chooser on the host display, the browse backend serves listing/creation primitives for the in-app browser; each backend is dual-face, its browser half filling ui-workspace directory-flow slots (no wire advertisement). |
 | `ctx.httpServer` | `core` | `webserver` | - | `connection`, `modules`, `hmr` | - | Plain node:http carrier: named-route registry, index transform taps, and the static dist fallback; web-transport plugins register their own routes. |
 | `ctx.clientModuleHost` | `core` | `modules` | - | `hmr` | - | Composes the __DSH_BOOT__ entry graph from an incremental dshClient scan, serves plugin bundles, and notifies rebuilt/graph-changed subscribers. |
 | `ctx.workflows` | `seam` | [`workflow`](../packages/workflow/workflow) | [`workflow-workerthread`](../packages/workflow/workflow-workerthread) | [`tool-workflow`](../packages/workflow/tool-workflow), [`tool-ralph`](../packages/workflow/tool-ralph) | - | One engine per context (bash shape, no named-provider registry); the general workflow and fixed Ralph consumers start runs whose agent() calls fan out through ctx.subagents. |
@@ -2241,6 +2241,7 @@ Imported as libraries by other packages; a `cordis.yml` cannot load them.
 - `@deepseek-ai/dsh-jsonrpc-demo` ([`packages/examples/jsonrpc-demo/src/index.ts`](../packages/examples/jsonrpc-demo/src/index.ts))
 - `@deepseek-ai/dsh-llm-mock-server` ([`packages/support/llm-mock-server/src/index.ts`](../packages/support/llm-mock-server/src/index.ts))
 - `@deepseek-ai/dsh-loader-smoke` ([`packages/support/loader-smoke/src/index.ts`](../packages/support/loader-smoke/src/index.ts))
+- `@deepseek-ai/dsh-native-command` ([`packages/util/native-command/src/index.ts`](../packages/util/native-command/src/index.ts))
 - `@deepseek-ai/dsh-paths` ([`packages/util/paths/src/index.ts`](../packages/util/paths/src/index.ts))
 - `@deepseek-ai/dsh-retention` ([`packages/util/retention/src/index.ts`](../packages/util/retention/src/index.ts))
 - `@deepseek-ai/dsh-scope` ([`packages/core/scope/src/index.ts`](../packages/core/scope/src/index.ts))
@@ -267,7 +267,6 @@ flowchart TD
  pkg_host_apiproxy --> pkg_invariants
  pkg_host_directory_picker --> pkg_invariants
  pkg_host_directory_picker_browse --> pkg_invariants
-  pkg_host_directory_picker_native --> pkg_invariants
  pkg_host_webserver --> pkg_invariants
  pkg_storage --> pkg_invariants
  pkg_subprocess --> pkg_invariants
@@ -355,6 +354,10 @@ flowchart TD
  pkg_client_ui_theme --> pkg_client_ui_primitives
  pkg_client_ui_theme --> pkg_client_ui_slots
  pkg_client_ui_theme --> pkg_invariants
+  pkg_host_directory_picker_native --> pkg_client_runtime
+  pkg_host_directory_picker_native --> pkg_client_ui_slots
+  pkg_host_directory_picker_native --> pkg_client_ui_workspace
+  pkg_host_directory_picker_native --> pkg_invariants
  pkg_lsp --> pkg_brand
  pkg_lsp --> pkg_invariants
  pkg_lsp --> pkg_llm
@@ -944,7 +947,6 @@ flowchart TD
 | [`host-apiproxy`](../packages/host/apiproxy) | `host` | [`invariants`](../packages/support/invariants) |
 | [`host-directory-picker`](../packages/host/directory-picker) | `host` | [`invariants`](../packages/support/invariants) |
 | [`host-directory-picker-browse`](../packages/host/directory-picker-browse) | `host` | [`invariants`](../packages/support/invariants) |
-| [`host-directory-picker-native`](../packages/host/directory-picker-native) | `host` | [`invariants`](../packages/support/invariants) |
 | [`host-webserver`](../packages/host/webserver) | `host` | [`invariants`](../packages/support/invariants) |
 | [`storage`](../packages/storage/storage) | `storage` | [`invariants`](../packages/support/invariants) |
 | [`subprocess`](../packages/subprocess/subprocess) | `subprocess` | [`invariants`](../packages/support/invariants) |
@@ -973,6 +975,7 @@ flowchart TD
 | [`client-ui-skill`](../packages/client/ui-skill) | `client` | [`client-connection`](../packages/client/connection), [`client-runtime`](../packages/client/runtime), [`client-ui-slash`](../packages/client/ui-slash), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
 | [`client-ui-subagent`](../packages/client/ui-subagent) | `client` | [`client-runtime`](../packages/client/runtime), [`client-ui-slash`](../packages/client/ui-slash), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
 | [`client-ui-theme`](../packages/client/ui-theme) | `client` | [`client-locale`](../packages/client/locale), [`client-runtime`](../packages/client/runtime), [`client-ui-primitives`](../packages/client/ui-primitives), [`client-ui-slots`](../packages/client/ui-slots), [`invariants`](../packages/support/invariants) |
+| [`host-directory-picker-native`](../packages/host/directory-picker-native) | `host` | [`client-runtime`](../packages/client/runtime), [`client-ui-slots`](../packages/client/ui-slots), [`client-ui-workspace`](../packages/client/ui-workspace), [`invariants`](../packages/support/invariants) |
 | [`lsp`](../packages/lsp/lsp) | `lsp` | [`brand`](../packages/util/brand), [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm) |
 | [`sandbox`](../packages/sandbox/sandbox) | `sandbox` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm) |
 | [`token-meter`](../packages/llm/token-meter) | `llm` | [`invariants`](../packages/support/invariants), [`llm`](../packages/llm/llm), [`session`](../packages/core/session) |
@@ -8,7 +8,7 @@
 export type {
  ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
  ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
-  DirectoryEntry, DirectoryListing, DirectoryPickerKind,
+  DirectoryEntry, DirectoryListing,
  WorkspaceApi, WorkspaceId, WorkspaceView,
  CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
  ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
@@ -863,12 +863,11 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
      },
    },
    host: {
-      describe: request => ok(request, { version: '0.0.0-fixture', cwd: '/tmp/fixture', attachedSessions, directoryPicker: 'browse' as const }),
-      pickDirectory: request => err(request, {
-        code: 'directory-picker-unavailable',
-        message: 'the fixture host serves the browse capability',
-        details: { capability: 'browse' },
-      }),
+      describe: request => ok(request, { version: '0.0.0-fixture', cwd: '/tmp/fixture', attachedSessions }),
+      // Deterministic native pick: the keyless lanes drive the full
+      // pick-then-adopt path without an OS chooser (design-mock content,
+      // same tree the browse primitives serve).
+      pickDirectory: request => ok(request, { path: `${FIXTURE_HOME}/Documents/project` }),
      listDirectory: (request) => {
        const target = request.payload.path ?? FIXTURE_HOME
        const children = childrenOf(target)
@@ -13,7 +13,7 @@ import { WebApiClient } from './web-api-client.ts'
 export type {
  ApiProxy, SessionsApi, SessionSummary, HostApi, EventsApi, MuxFrame, HostFrame,
  ApprovalResponsePayload, QuestionResponsePayload, HistoryEntry, ToolEventView,
-  DirectoryEntry, DirectoryListing, DirectoryPickerKind,
+  DirectoryEntry, DirectoryListing,
  ToolCallView, ToolResultView, WorkspaceApi, WorkspaceId, WorkspaceView,
  CommandsApi, CommandDescriptor, SkillsApi, SkillEntry,
  ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
@@ -75,7 +75,7 @@ describe('connection lifecycle', () => {
    try {
      await vi.waitFor(() => { expect(describeCalls).toBe(2) }) // retried after backoff
      expect(connected).toBe(0) // never announced during the failed generation
-      gate.resolve(ok({ version: '0', cwd: '/f', attachedSessions: 0, directoryPicker: 'browse' as const }))
+      gate.resolve(ok({ version: '0', cwd: '/f', attachedSessions: 0 }))
      await vi.waitFor(() => { expect(connected).toBe(1) })
    } finally {
      controller.stop()
@@ -199,7 +199,7 @@ describe('connection lifecycle', () => {
    controller.start()
    try {
      await vi.waitFor(() => { expect(describeCalls).toBe(3) })
-      gate.resolve(ok({ version: '0', cwd: '/f', attachedSessions: 0, directoryPicker: 'browse' as const }))
+      gate.resolve(ok({ version: '0', cwd: '/f', attachedSessions: 0 }))
      await vi.waitFor(() => { expect(connected).toBe(1) })
      expect(states).toEqual(['reconnecting', 'connected']) // two failures, one reconnecting emission
    } finally {
@@ -63,8 +63,8 @@ export class FakeApiClient implements IApiClient {
    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; directoryPicker: 'native' | 'browse' }>> =
-    () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0, directoryPicker: 'browse' 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 }))
  onOpenPath: (payload: unknown) => Promise<RpcResponse<{ opened: true }>> =
@@ -23,7 +23,7 @@ export type { SessionListPhase } from './sessions/manager.ts'
 export type { WorkspaceListPhase } from './workspaces/manager.ts'
 export type { WorkspaceListState } from './workspaces/service.ts'
 export type {
-  DirectoryEntry, DirectoryListing, DirectoryPickerKind, WorkspaceId, WorkspaceView,
+  DirectoryEntry, DirectoryListing, WorkspaceId, WorkspaceView,
 } from '@deepseek-ai/dsh-client-connection/client'
 // Runtime owns the snapshot store; web-react only binds it to React.
 export { createSnapshotStore, defineStore, shallowEqual } from './contract/store.ts'
@@ -2,7 +2,7 @@

 import type { Context } from 'cordis'
 import type {
-  DirectoryListing, DirectoryPickerKind, IApiClient, RpcError,
+  DirectoryListing, IApiClient, RpcError,
  SessionId, WorkspaceId, WorkspaceView,
 } from '@deepseek-ai/dsh-client-connection/client'
 import type { SnapshotStore } from '../contract/store.ts'
@@ -191,21 +191,6 @@ export class WorkspacesService {
    return response.result.value.path
  }

-  /**
-   * The directory-picking interaction the Host composed — the fact the picker
-   * UI branches on (`native` opens the native chooser; `browse` opens the
-   * in-app browser). Read per flow open: one describe round trip, no cache to
-   * go stale across reconnects.
-   * @returns the Host's advertised picker kind.
-   */
-  async directoryPickerKind(): Promise<DirectoryPickerKind> {
-    const response = await this.api.host.describe({})
-    if (!response.result.ok) {
-      throw new Error(`host describe failed: ${response.result.error.message}`)
-    }
-    return response.result.value.directoryPicker
-  }
-
  /**
   * List one directory level through the Host's `browse` capability.
   * @param path - absolute directory to list; absent lists the Host home directory.
@@ -81,8 +81,8 @@ export class FakeApiClient implements IApiClient {
    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; directoryPicker: 'native' | 'browse' }>> =
-    () => Promise.resolve(ok({ version: '0-fake', cwd: '/f', attachedSessions: 0, directoryPicker: 'browse' 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 }))
  onOpenPath: (payload: unknown) => Promise<RpcResponse<{ opened: true }>> =
@@ -238,15 +238,6 @@ describe('WorkspacesService', () => {
    await expect(workspaces.pickDirectory()).rejects.toThrow(/no chooser/)
  })

-  it('reads the picker kind from describe per call, failing loud on an unreachable host', async () => {
-    const ctx = new Context()
-    const api = new FakeApiClient()
-    const workspaces = new WorkspacesService(ctx, api, new SessionsService(ctx, api))
-    await expect(workspaces.directoryPickerKind()).resolves.toBe('browse')
-    api.onDescribe = () => Promise.resolve(err({ code: 'internal', message: 'down', details: {} }))
-    await expect(workspaces.directoryPickerKind()).rejects.toThrow(/host describe failed/)
-  })
-
  it('passes listings and creation through the browse wire, wrapping business failures', async () => {
    const ctx = new Context()
    const api = new FakeApiClient()
@@ -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-workspace/README.md
-README.md: deaa25184f5ddbfc5980033ce60cef43577ff33c
-README.zh.md: e14e8ca6a2e3d65ce5fc403291e45ebc03598e04
+README.md: 8acf819121b46512d38b39ff858bb2bf797cfe96
+README.zh.md: e97d93f7e38d00af91b43f0df9fb0e3b17ae8ed5
@@ -4,7 +4,7 @@ English | [中文](README.zh.md)

 Shared Workspace picker plugin. `WorkspaceBrowser` is registered into the sidebar's `sidebar.workspaces` slot and `WorkspacePicker` into the page-local Session Intent hero's `conversation.hero.workspace` slot, so both surfaces use the same menu and creation flow.

-The picker lists real Host Workspace entities through the global `useWorkspaces` hook. Selecting a Workspace invokes the slot owner's `onPick` callback to retarget the frontend Session object. The flat **Open local folder...** action renders only when the Host advertises the `native` picker interaction (read per flow open through `host.describe`); `browse` — until its in-app browser UI lands — and unknown kinds hide the entry, the seam's documented default. When shown, it delegates to the Host's native single-directory picker, adopts a returned path through the object layer, and selects the committed Workspace only after its list projection has refreshed; cancellation is silent, and errors remain retryable. **Create a new workspace** retains the name dialog and disables names already present in that list, while the Host remains authoritative for concurrent or non-UI callers. The runtime Session and Workspace services own materialization. The Workspace row's Delete action opens a confirmation that states the retention boundary, blocks duplicate submission, and keeps failures open; success removes the group while its Sessions remain under Ungrouped.
+The picker lists real Host Workspace entities through the global `useWorkspaces` hook. Selecting a Workspace invokes the slot owner's `onPick` callback to retarget the frontend Session object. Each registration declares a **directory-flow child hole** (`single` kind: `conversation.hero.workspace.directoryFlow` / `sidebar.workspaces.directoryFlow`) that the composed picker package's client half fills with its picking interaction — the [`-native`](../../host/directory-picker-native/README.md) backend's renderless OS-chooser driver today, an in-app browsing dialog under a `-browse` composition. The flat **Open local folder...** action renders only while the surface's hole is occupied (occupancy read per menu render; an empty hole means the composition has no picking affordance — the seam's documented no-flow default). This package owns the trigger and the adoption: the occupant reports one picked path per open through the hole's owner conversation (`open`/`busy`/`onPicked`/`onCancel`/`onError`), and the owner adopts it through the object layer, selecting the committed Workspace only after its list projection has refreshed; cancellation is silent, and errors land in the retryable folder dialog whose **Choose again** reopens the flow. **Create a new workspace** retains the name dialog and disables names already present in that list, while the Host remains authoritative for concurrent or non-UI callers. The runtime Session and Workspace services own materialization. The Workspace row's Delete action opens a confirmation that states the retention boundary, blocks duplicate submission, and keeps failures open; success removes the group while its Sessions remain under Ungrouped.

 Both target slots are declared by other plugins, so `apply` registers through declaration-aware deferral and re-registers after a declaring slot is restored.

@@ -19,4 +19,4 @@ None; this package neither assembles nor sends a provider request.
 ## Known Limitations and Deferred Work

 - **No Session deletion control** — the existing Session menu row remains visual-only; Workspace registration deletion does not delete Sessions.
- **Native folder selection depends on the local Host carrier** — fixture-only or remote browser deployments cannot open a local operating-system dialog; platform failures are shown in a retryable modal.
+- **Native folder selection depends on the local Host carrier** — under the `-native` composition, fixture-only or remote browser deployments cannot open a local operating-system dialog; platform failures are shown in a retryable modal. Remote-capable picking is the `-browse` composition's in-app flow.
@@ -4,7 +4,7 @@

 共享 Workspace 选择器插件。`WorkspaceBrowser` 注册到侧边栏的 `sidebar.workspaces` slot，`WorkspacePicker` 注册到页面局部 Session Intent 主视觉区的 `conversation.hero.workspace` slot，因此两个表层使用同一菜单和创建流程。

-该选择器通过全局 `useWorkspaces` hook 列出真实的 Host Workspace 实体。选择 Workspace 会调用 slot owner 的 `onPick` 回调，重新定位前端 Session 对象。平铺显示的 **打开本地文件夹…** 操作仅在 Host 广播 `native` 选择交互时渲染（每次流程打开时通过 `host.describe` 读取）；`browse`（在其应用内浏览器 UI 落地之前）以及未知 kind 都会隐藏该入口，即 seam 文档化的默认行为。显示时它会委托 Host 的原生单目录选择器，通过对象层接纳返回的路径，并等待 Workspace 列表投影刷新后才选中已提交的 Workspace；取消操作不会显示提示，发生错误后仍可重试。**创建新工作区** 操作保留名称对话框，并禁用列表中已有的名称，而 Host 对并发或非 UI 调用方仍具有最终决定权。运行时 Session 与 Workspace 服务负责物化。Workspace 行内的 Delete 操作会打开确认框，说明保留边界、阻止重复提交，并在失败时保持打开；成功后，该分组会被移除，其 Session 则留在 Ungrouped 下。
+该选择器通过全局 `useWorkspaces` hook 列出真实的 Host Workspace 实体。选择 Workspace 会调用 slot owner 的 `onPick` 回调，重新定位前端 Session 对象。每个注册各自声明一个**目录流子洞**（`single` kind：`conversation.hero.workspace.directoryFlow`／`sidebar.workspaces.directoryFlow`），由组合的选择器包 client half 填入其选取交互——今天是 [`-native`](../../host/directory-picker-native/README.md) 后端的无渲染 OS 选择器驱动，`-browse` 组合下则是应用内浏览对话框。平铺显示的 **打开本地文件夹…** 操作仅在本表层的洞被占用时渲染（每次菜单渲染读取占用状态；洞为空意味着该组合没有选目录能力——seam 文档化的无流程默认行为）。本包持有触发与接纳：占用者经洞的 owner 会话（`open`/`busy`/`onPicked`/`onCancel`/`onError`）每次打开上报一个所选路径，owner 通过对象层接纳它，并等待 Workspace 列表投影刷新后才选中已提交的 Workspace；取消操作不会显示提示，错误落入可重试的文件夹对话框，其 **重新选择** 会重新打开流程。**创建新工作区** 操作保留名称对话框，并禁用列表中已有的名称，而 Host 对并发或非 UI 调用方仍具有最终决定权。运行时 Session 与 Workspace 服务负责物化。Workspace 行内的 Delete 操作会打开确认框，说明保留边界、阻止重复提交，并在失败时保持打开；成功后，该分组会被移除，其 Session 则留在 Ungrouped 下。

 两个目标 slot 都由其他插件声明，因此 `apply` 通过声明感知的延迟机制完成注册，并在声明该 slot 的插件恢复后重新注册。

@@ -19,4 +19,4 @@
 ## 已知限制与暂缓事项

 - **没有 Session 删除控件**：现有 Session 菜单行仍仅提供视觉效果；删除 Workspace 注册记录不会删除 Session。
- **原生文件夹选择依赖本地 Host 载体**：仅使用 fixture（测试前置数据）的部署或远程浏览器部署无法打开本地操作系统对话框；模态框会显示平台故障，并允许重试。
+- **原生文件夹选择依赖本地 Host 载体**：在 `-native` 组合下，仅使用 fixture（测试前置数据）的部署或远程浏览器部署无法打开本地操作系统对话框；模态框会显示平台故障，并允许重试。可远程的选取是 `-browse` 组合的应用内流程。
@@ -253,8 +253,8 @@ export function WorkspaceBrowser({
  deleteWorkspace,
  insertSessionBefore,
  createWorkspace,
-  pickDirectory,
-  directoryPickerKind,
+  hasDirectoryFlow,
+  renderSlot,
 }: WorkspaceBrowserProps) {
  const workspaces = useWorkspaces(state => state.items)
  const groupBy = useStore(s => s.groupBy)
@@ -372,8 +372,8 @@ export function WorkspaceBrowser({
          anchorRef={wsPlusRef}
          useWorkspaces={useWorkspaces}
          createWorkspace={createWorkspace}
-          pickDirectory={pickDirectory}
-          directoryPickerKind={directoryPickerKind}
+          hasDirectoryFlow={hasDirectoryFlow}
+          renderDirectoryFlow={owner => renderSlot('sidebar.workspaces.directoryFlow', owner)}
          createOnly
          side="right"
          onPick={(workspaceId) => {
@@ -2,18 +2,20 @@
 * Workspace pick/create flow. WorkspaceCreateFlow is the reusable core
 * (menu + path/create dialogs) consumed directly by WorkspaceBrowser (same
 * package) and wrapped by WorkspacePicker for the conversation empty-state
- * slot registration.
+ * slot registration. Directory picking itself lives in the composed flow
+ * package's slot occupant (see the contract module doc): this core only
+ * opens the flow, adopts the picked path, and owns the error surface.
 */
-import type { RefObject } from 'react'
-import { useCallback, useEffect, useRef, useState } from 'react'
+import type { ReactNode, RefObject } from 'react'
+import { useCallback, useRef, useState } from 'react'
 import {
  Button, IconFolderClose16, IconPlusOutline16, Menu, Modal, type MenuEntry,
 } from '@deepseek-ai/dsh-client-ui-primitives'
 import {
  WorkspaceCreateError,
-  type DirectoryPickerKind, type WorkspaceId, type WorkspaceListState, type WorkspaceView,
+  type WorkspaceId, type WorkspaceListState, type WorkspaceView,
 } from '@deepseek-ai/dsh-client-runtime/client'
-import type { WorkspacePickerProps } from './contract/slots.ts'
+import type { DirectoryFlowOwnerProps, WorkspacePickerProps } from './contract/slots.ts'
 import css from './WorkspacePicker.module.css'

 const OPEN_LOCAL_FOLDER = '::open-local-folder'
@@ -31,10 +33,10 @@ export interface WorkspaceCreateFlowProps {
  useWorkspaces: <S>(selector: (state: WorkspaceListState) => S) => S
  /** Create or adopt a real Host Workspace. */
  createWorkspace: (input: { name: string } | { path: string }) => Promise<WorkspaceView>
-  /** Open the Host's native single-directory picker. */
-  pickDirectory: () => Promise<string | null>
-  /** The Host's advertised picker interaction (read per flow open); gates which picking affordance renders. */
-  directoryPickerKind: () => Promise<DirectoryPickerKind>
+  /** Whether this surface's directory-flow hole is occupied (read per menu render; empty hides the local-folder entry). */
+  hasDirectoryFlow: () => boolean
+  /** Render this surface's directory-flow hole with the owner conversation (the entry's narrowed renderSlot). */
+  renderDirectoryFlow: (owner: DirectoryFlowOwnerProps) => ReactNode
  /** A real Workspace was picked or created. */
  onPick: (workspaceId: WorkspaceId) => void
  /** Close the popover (outside click / Escape / post-pick). */
@@ -57,8 +59,8 @@ export function WorkspaceCreateFlow({
  anchorRef,
  useWorkspaces,
  createWorkspace,
-  pickDirectory,
-  directoryPickerKind,
+  hasDirectoryFlow,
+  renderDirectoryFlow,
  onPick,
  onClose,
  createOnly = false,
@@ -75,6 +77,7 @@ export function WorkspaceCreateFlow({
  const [workspaceName, setWorkspaceName] = useState('')
  const [creating, setCreating] = useState(false)
  const [modalError, setModalError] = useState<string | null>(null)
+  const [flowOpen, setFlowOpen] = useState(false)
  const [pickingFolder, setPickingFolder] = useState(false)
  const [folderConflict, setFolderConflict] = useState(false)
  const composingRef = useRef(false)
@@ -82,36 +85,12 @@ export function WorkspaceCreateFlow({
  const duplicateWorkspaceName = !creating && normalizedWorkspaceName !== ''
    && workspaces.some(workspace => workspace.title === normalizedWorkspaceName)

-  // The advertised interaction gates the picking affordance: 'native' is the
-  // only kind pickDirectory() can serve, so its entry renders under that kind
-  // alone; 'browse' (until the in-app browser UI lands) and unknown kinds
-  // hide the entry, the seam's documented unknown-kind default. Re-read per
-  // flow open — no cache to go stale across reconnects.
-  const [nativePicker, setNativePicker] = useState(false)
-  useEffect(() => {
-    if (!open) {
-      // Close discards the answer: a reconnect or HMR can swap the composed
-      // backend while the menu is closed, and the reopened menu must never
-      // paint the previous host's entry before the fresh read lands.
-      setNativePicker(false)
-      return
-    }
-    // Reset before each read: the injected reader can also change identity
-    // while the flow stays open, and that prior answer must not leak either;
-    // a settlement from a superseded read is discarded via the
-    // cleanup-toggled flag.
-    setNativePicker(false)
-    let stale = false
-    void directoryPickerKind()
-      .then((kind) => { if (!stale) setNativePicker(kind === 'native') })
-      // A failed describe hides the entry too: the same Host that cannot
-      // answer describe cannot serve pickDirectory.
-      .catch(() => { if (!stale) setNativePicker(false) })
-    return () => { stale = true }
-  }, [open, directoryPickerKind])
-
+  // The occupied hole gates the picking affordance: with no composed flow the
+  // entry simply is not there (the seam's documented no-flow default). Read
+  // per render while the menu is open — registrations land through plugin
+  // activation, and the menu re-renders on every toggle.
  const createEntries: MenuEntry[] = [
-    ...(nativePicker
+    ...(hasDirectoryFlow()
      ? [{ id: OPEN_LOCAL_FOLDER, label: 'Open local folder…', icon: <IconFolderClose16 size={16} />, disabled: pickingFolder }]
      : []),
    { id: CREATE_NEW, label: 'Create a new workspace', icon: <IconPlusOutline16 size={16} />, disabled: pickingFolder },
@@ -134,15 +113,10 @@ export function WorkspaceCreateFlow({
    setModalError(null)
  }

-  const openLocalFolder = (): void => {
-    onClose()
-    setModalKind(null)
-    setModalError(null)
-    setFolderConflict(false)
-    setPickingFolder(true)
-    void pickDirectory().then(async (path) => {
-      if (path === null) return
-      const workspace = await createWorkspace({ path })
+  /** Adopt a picked directory; failures land in the folder-error dialog (Choose again reopens the flow). */
+  const adoptDirectory = (path: string): Promise<void> =>
+    createWorkspace({ path }).then((workspace) => {
+      setFlowOpen(false)
      onPick(workspace.workspaceId)
    }).catch((reason: unknown) => {
      setFolderConflict(
@@ -150,8 +124,33 @@ export function WorkspaceCreateFlow({
        && reason.rpcError.code === 'workspace-name-conflict',
      )
      setModalError(reason instanceof Error ? reason.message : String(reason))
+      setFlowOpen(false)
      setModalKind('folder-error')
-    }).finally(() => { setPickingFolder(false) })
+    })
+
+  const openLocalFolder = (): void => {
+    onClose()
+    setModalKind(null)
+    setModalError(null)
+    setFolderConflict(false)
+    setFlowOpen(true)
+  }
+
+  /** Owner side of the flow conversation: adopt keeps the flow open (busy) until the Host answers. */
+  const flowOwner: DirectoryFlowOwnerProps = {
+    open: flowOpen,
+    busy: pickingFolder,
+    onPicked: (path) => {
+      setPickingFolder(true)
+      void adoptDirectory(path).finally(() => { setPickingFolder(false) })
+    },
+    onCancel: () => { setFlowOpen(false) },
+    onError: (message) => {
+      setFlowOpen(false)
+      setFolderConflict(false)
+      setModalError(message)
+      setModalKind('folder-error')
+    },
  }

  const handleSelect = (id: string): void => {
@@ -205,6 +204,7 @@ export function WorkspaceCreateFlow({
        getAnchorRect={getAnchorRect}
      />
      {open && workspaceSnapshot.phase === 'pending' && <div className={css.menuStatus} role="status">Loading workspaces…</div>}
+      {renderDirectoryFlow(flowOwner)}
      <Modal
        open={modalKind === 'folder-error'}
        onClose={closeModal}
@@ -282,8 +282,8 @@ export function WorkspacePicker({
  onPick,
  onClose,
  createWorkspace,
-  pickDirectory,
-  directoryPickerKind,
+  hasDirectoryFlow,
+  renderSlot,
 }: WorkspacePickerProps) {
  return (
    <WorkspaceCreateFlow
@@ -291,8 +291,8 @@ export function WorkspacePicker({
      anchorRef={anchorRef}
      useWorkspaces={useWorkspaces}
      createWorkspace={createWorkspace}
-      pickDirectory={pickDirectory}
-      directoryPickerKind={directoryPickerKind}
+      hasDirectoryFlow={hasDirectoryFlow}
+      renderDirectoryFlow={owner => renderSlot('conversation.hero.workspace.directoryFlow', owner)}
      selectedId={selectedId}
      onPick={onPick}
      onClose={onClose}
@@ -7,21 +7,74 @@
 *   consumes the shell's two-fact owner share (wide / expandSidebar).
 * - WorkspacePicker fills the conversation empty-state hole (menu +
 *   create dialogs shared with the browser).
+ *
+ * Each registration also declares one **directory-flow hole** (`single`
+ * kind): the slot a composed picker package's client half fills with its
+ * picking interaction — a renderless native-chooser driver or an in-app
+ * browsing dialog. ui-workspace owns the trigger (the "Open local folder…"
+ * menu entry, shown only while the hole is occupied) and the adoption
+ * semantics (`createWorkspace({ path })`, the conflict/error dialog, Choose
+ * again); the occupant owns everything between `open` and the picked path.
+ * Two holes exist because the two menu surfaces are independent slot entries
+ * and a hole has exactly one declaring entry — they carry the same owner
+ * contract and the same occupant.
 */
-import type { PropsRuntime, PropsStore } from '@deepseek-ai/dsh-client-ui-slots'
+import type { PropsRenderSlots, PropsRuntime, PropsStore } from '@deepseek-ai/dsh-client-ui-slots'
 // Type-only: pull the owner SlotMap merges into programs that resolve the
 // runtime shares below.
 import type {} from '@deepseek-ai/dsh-client-ui-sidebar/client'
 import type {} from '@deepseek-ai/dsh-client-ui-conversation/client'
-import type { DirectoryPickerKind, SessionId, WorkspaceId, WorkspaceView } from '@deepseek-ai/dsh-client-runtime/client'
+import type { SessionId, WorkspaceId, WorkspaceView } from '@deepseek-ai/dsh-client-runtime/client'
 import type { createWorkspaceViewStore } from '../stores.ts'

+/**
+ * Owner share of the directory-flow holes: the complete conversation between
+ * the trigger surface and the picking interaction. The occupant reads `open`
+ * to run/render its interaction and reports exactly one outcome per open.
+ */
+export interface DirectoryFlowOwnerProps {
+  /** True while a picking interaction is requested; flipping back to false withdraws the request. */
+  open: boolean
+  /** True while the owner adopts a picked path (`createWorkspace` in flight); occupants disable their commit affordances. */
+  busy: boolean
+  /** The operator picked a directory (absolute host path); the owner adopts it. */
+  onPicked: (path: string) => void
+  /** The operator dismissed the interaction; the owner just closes the flow. */
+  onCancel: () => void
+  /** The interaction itself failed (chooser missing, listing denied); the owner shows its error surface. */
+  onError: (message: string) => void
+}
+
+declare module '@deepseek-ai/dsh-client-ui-slots' {
+  interface SlotMap {
+    /** Directory-flow hole under the conversation empty-state picker (declared by the WorkspacePicker entry). */
+    'conversation.hero.workspace.directoryFlow': { kind: 'single'; scope: 'root'; owner: DirectoryFlowOwnerProps }
+    /** Directory-flow hole under the sidebar browsing region (declared by the WorkspaceBrowser entry). */
+    'sidebar.workspaces.directoryFlow': { kind: 'single'; scope: 'root'; owner: DirectoryFlowOwnerProps }
+  }
+}
+
+/** The two directory-flow holes; a flow package's client half registers its one component into both. */
+export type DirectoryFlowSlotName =
+  | 'conversation.hero.workspace.directoryFlow'
+  | 'sidebar.workspaces.directoryFlow'
+
+/** Directory-picking share both trigger surfaces consume. */
+export type DirectoryPickingInjected = {
+  /**
+   * Whether this surface's directory-flow hole is occupied — read when the
+   * menu opens; an empty hole hides the "Open local folder…" entry (the
+   * no-flow composition simply has no picking affordance).
+   */
+  hasDirectoryFlow: () => boolean
+}
+
 /**
 * Browser-private injected share (arrives via the register inject factory).
 * Data reads use the global framework hooks; these are the Host actions the
 * browsing region drives.
 */
-export type WorkspaceBrowserInjected = {
+export type WorkspaceBrowserInjected = DirectoryPickingInjected & {
  /**
   * Start a New Session in a Workspace: reuse-or-create its blank session
   * and open it; with no workspace, clear the selection into the New Session
@@ -42,15 +95,12 @@ export type WorkspaceBrowserInjected = {
  insertSessionBefore: (workspaceId: WorkspaceId, sessionId: SessionId, beforeSessionId?: SessionId) => Promise<void>
  /** Explicitly create or adopt a real Workspace before targeting a Session. */
  createWorkspace: (input: { name: string } | { path: string }) => Promise<WorkspaceView>
-  /** Ask the local Host to open its native single-directory picker. */
-  pickDirectory: () => Promise<string | null>
-  /** The Host's advertised picker interaction (read per flow open); gates which picking affordance renders. */
-  directoryPickerKind: () => Promise<DirectoryPickerKind>
 }

 /** Full browser props: shell owner share + viewing store + injected actions. */
 export type WorkspaceBrowserProps =
  PropsRuntime<'sidebar.workspaces'>
+  & PropsRenderSlots<'sidebar.workspaces.directoryFlow'>
  & PropsStore<ReturnType<typeof createWorkspaceViewStore>>
  & WorkspaceBrowserInjected

@@ -59,13 +109,9 @@ export type WorkspaceBrowserProps =
 * callback; this callback creates only the real Host Workspace. A type alias
 * supplies the implicit index signature required by the registry.
 */
-export type WorkspacePickerInjected = {
+export type WorkspacePickerInjected = DirectoryPickingInjected & {
  /** Explicitly create or adopt a real Workspace before targeting a Session. */
  createWorkspace: (input: { name: string } | { path: string }) => Promise<WorkspaceView>
-  /** Ask the local Host to open its native single-directory picker. */
-  pickDirectory: () => Promise<string | null>
-  /** The Host's advertised picker interaction (read per flow open); gates which picking affordance renders. */
-  directoryPickerKind: () => Promise<DirectoryPickerKind>
 }

 /**
@@ -74,4 +120,6 @@ export type WorkspacePickerInjected = {
 * currency, so one composed type serves both registrations.
 */
 export type WorkspacePickerProps =
-  PropsRuntime<'conversation.hero.workspace'> & WorkspacePickerInjected
+  PropsRuntime<'conversation.hero.workspace'>
+  & PropsRenderSlots<'conversation.hero.workspace.directoryFlow'>
+  & WorkspacePickerInjected
@@ -3,9 +3,12 @@
 * the sidebar shell's `sidebar.workspaces` hole (the whole browsing region),
 * and WorkspacePicker fills the conversation hero's picker hole
 * (`conversation.hero.workspace` — both hero forms). Both read real Host
- * Workspaces through the global useWorkspaces hook. Export discipline:
+ * Workspaces through the global useWorkspaces hook, and each declares its
+ * own `single` directory-flow child hole for the composed picker package's
+ * client half (see the contract module doc). Export discipline:
 * packages/client/AGENTS.md.
 */
+import { deferRegistration } from '@deepseek-ai/dsh-client-ui-slots'
 import type { ClientContext } from '@deepseek-ai/dsh-client-runtime/client'
 import type { WorkspaceBrowserInjected, WorkspacePickerInjected } from './contract/slots.ts'
 import { createWorkspaceViewStore } from './stores.ts'
@@ -13,6 +16,7 @@ import { WorkspaceBrowser } from './WorkspaceBrowser.tsx'
 import { WorkspacePicker } from './WorkspacePicker.tsx'

 export type {
+  DirectoryFlowOwnerProps, DirectoryFlowSlotName, DirectoryPickingInjected,
  WorkspaceBrowserInjected, WorkspaceBrowserProps, WorkspacePickerInjected, WorkspacePickerProps,
 } from './contract/slots.ts'

@@ -44,50 +48,40 @@ export function apply(ctx: ClientContext): void {
      await ctx.workspaces.insertSessionBefore(workspaceId, sessionId, beforeSessionId)
    },
    createWorkspace: input => ctx.workspaces.create(input),
-    pickDirectory: () => ctx.workspaces.pickDirectory(),
-    directoryPickerKind: () => ctx.workspaces.directoryPickerKind(),
+    hasDirectoryFlow: () => ctx.slots.entries('sidebar.workspaces.directoryFlow').length > 0,
  })
  const pickerInjected = (): WorkspacePickerInjected => ({
    createWorkspace: input => ctx.workspaces.create(input),
-    pickDirectory: () => ctx.workspaces.pickDirectory(),
-    directoryPickerKind: () => ctx.workspaces.directoryPickerKind(),
+    hasDirectoryFlow: () => ctx.slots.entries('conversation.hero.workspace.directoryFlow').length > 0,
  })
-  // Declaration-aware registration: each owner's declaring apply may activate
-  // after this one (entry activation order is unconstrained), and a register
-  // into an undeclared slot throws. Register once the declaration is on the
-  // ledger; the subscription also re-registers after an HMR collapse
-  // re-declares the slot (the cascade disposed our entry with it).
+  // Declaration-aware registration (deferRegistration): each owner's
+  // declaring apply may activate after this one, and a register into an
+  // undeclared slot throws; the deferral also re-registers after an HMR
+  // collapse re-declares the slot. Each registration declares its own
+  // directory-flow child hole in the same call (declaration = render
+  // authorization, one table).
  ctx.effect(() => {
-    const registrations = [
-      {
-        name: 'sidebar.workspaces' as const,
-        component: WorkspaceBrowser,
-        register: () => ctx.slots.register(
-          { name: 'sidebar.workspaces', store: createWorkspaceViewStore(), inject: browserInjected },
+    const deferred = [
+      deferRegistration(ctx.slots, 'sidebar.workspaces', WorkspaceBrowser, () =>
+        ctx.slots.register(
+          {
+            name: 'sidebar.workspaces',
+            children: { 'sidebar.workspaces.directoryFlow': { kind: 'single', scope: 'root' } },
+            store: createWorkspaceViewStore(),
+            inject: browserInjected,
+          },
          WorkspaceBrowser,
-        ),
-      },
-      {
-        name: 'conversation.hero.workspace' as const,
-        component: WorkspacePicker,
-        register: () => ctx.slots.register(
-          { name: 'conversation.hero.workspace', inject: pickerInjected },
+        )),
+      deferRegistration(ctx.slots, 'conversation.hero.workspace', WorkspacePicker, () =>
+        ctx.slots.register(
+          {
+            name: 'conversation.hero.workspace',
+            children: { 'conversation.hero.workspace.directoryFlow': { kind: 'single', scope: 'root' } },
+            inject: pickerInjected,
+          },
          WorkspacePicker,
-        ),
-      },
+        )),
    ]
-    const disposers = new Map<string, () => void>()
-    const tryRegister = (entry: (typeof registrations)[number]): void => {
-      if (ctx.slots.spec(entry.name) === undefined) return
-      if (ctx.slots.entries(entry.name).some(e => e.component === entry.component)) return
-      disposers.set(entry.name, entry.register())
-    }
-    const unsubscribers = registrations.map(entry =>
-      ctx.slots.subscribe(entry.name, () => { tryRegister(entry) }))
-    for (const entry of registrations) tryRegister(entry)
-    return () => {
-      for (const unsubscribe of unsubscribers) unsubscribe()
-      for (const dispose of disposers.values()) dispose()
-    }
+    return () => { for (const entry of deferred) entry.dispose() }
  }, 'ui-workspace: browser + picker registrations')
 }
@@ -14,18 +14,16 @@ async function bench() {
    path: 'name' in input ? `/projects/${input.name}` : input.path,
    title: 'new', sessionIds: [], createdAt: '0', updatedAt: '0',
  }))
-  const pickDirectory = vi.fn(async () => '/tmp/picked')
-  const directoryPickerKind = vi.fn(async () => 'native' as const)
  const startSession = vi.fn()
  const rename = vi.fn(async () => ({}))
  const insertSessionBefore = vi.fn(async () => ({}))
  const open = vi.fn()
  const clear = vi.fn()
  ctx.provide('workspaces', {
-    create, pickDirectory, directoryPickerKind, startSession, rename, insertSessionBefore,
+    create, startSession, rename, insertSessionBefore,
  } as never)
  ctx.provide('sessions', { open, clear } as never)
-  return { ctx, slots: ctx.get('slots') as SlotsService, create, pickDirectory, directoryPickerKind, startSession, rename, insertSessionBefore, open, clear }
+  return { ctx, slots: ctx.get('slots') as SlotsService, create, startSession, rename, insertSessionBefore, open, clear }
 }

 type HoleName = 'sidebar.workspaces' | 'conversation.hero.workspace' | 'conversation.empty.workspace'
@@ -74,18 +72,30 @@ describe('ui-workspace apply', () => {
    expect(b.insertSessionBefore).toHaveBeenCalledWith('ws', 's1', 's2')
    await browser.createWorkspace({ name: 'project' })
    expect(b.create).toHaveBeenCalledWith({ name: 'project' })
-    await browser.pickDirectory()
-    expect(b.pickDirectory).toHaveBeenCalledOnce()
-    await browser.directoryPickerKind()
-    expect(b.directoryPickerKind).toHaveBeenCalledOnce()

    const picker = (b.slots.entries('conversation.hero.workspace')[0]!.inject as () => WorkspacePickerInjected)()
    await picker.createWorkspace({ path: '/tmp/project' })
    expect(b.create).toHaveBeenCalledWith({ path: '/tmp/project' })
-    await picker.pickDirectory()
-    expect(b.pickDirectory).toHaveBeenCalledTimes(2)
-    await picker.directoryPickerKind()
-    expect(b.directoryPickerKind).toHaveBeenCalledTimes(2)
+  })
+
+  it('declares the two directory-flow holes and reports their occupancy per surface', async () => {
+    const b = await bench()
+    declare(b.slots, 'sidebar.workspaces', 'conversation.hero.workspace')
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    // Registration declared the child holes (declaration = render authorization).
+    expect(b.slots.spec('sidebar.workspaces.directoryFlow')).toMatchObject({ kind: 'single' })
+    expect(b.slots.spec('conversation.hero.workspace.directoryFlow')).toMatchObject({ kind: 'single' })
+
+    const browser = (b.slots.entries('sidebar.workspaces')[0]!.inject as () => WorkspaceBrowserInjected)()
+    const picker = (b.slots.entries('conversation.hero.workspace')[0]!.inject as () => WorkspacePickerInjected)()
+    expect(browser.hasDirectoryFlow()).toBe(false)
+    expect(picker.hasDirectoryFlow()).toBe(false)
+    // A flow occupant flips exactly its own surface.
+    const dispose = b.slots.register({ name: 'sidebar.workspaces.directoryFlow' } as never, () => null)
+    expect(browser.hasDirectoryFlow()).toBe(true)
+    expect(picker.hasDirectoryFlow()).toBe(false)
+    dispose()
+    expect(browser.hasDirectoryFlow()).toBe(false)
  })

  it('unregisters every entry on teardown', async () => {
@@ -59,8 +59,8 @@ function mount(overrides: Partial<WorkspaceBrowserProps> = {}) {
    deleteWorkspace: vi.fn(async () => {}),
    insertSessionBefore: vi.fn(async () => {}),
    createWorkspace: vi.fn(async () => workspace('created', [])),
-    pickDirectory: vi.fn(async () => null),
-    directoryPickerKind: vi.fn(async () => 'native' as const),
+    hasDirectoryFlow: () => true,
+    renderSlot: ((_name: string, owner: { open: boolean }) => (owner.open ? <div data-testid="directory-flow" /> : null)) as never,
    ...overrides,
  }
  const view = render(<WorkspaceBrowser {...props} />)
@@ -264,13 +264,11 @@ describe('WorkspaceBrowser', () => {
    }
  })

-  it('rail create-workspace toggles the create-only picker in place, without expanding', async () => {
+  it('rail create-workspace toggles the create-only picker in place, without expanding', () => {
    const expandSidebar = vi.fn()
    mount({ wide: false, expandSidebar, useWorkspaces: hook(workspaceState([workspace('alpha', [])])) })
    fireEvent.click(screen.getByRole('button', { name: 'Create workspace' }))
    expect(expandSidebar).not.toHaveBeenCalled()
-    // Flush the advertised-kind read that gates the local-folder entry.
-    await act(async () => {})
    // createOnly: existing workspaces are not listed, only the create actions.
    expect(screen.queryByRole('menuitem', { name: 'alpha' })).toBeNull()
    expect(screen.getByRole('menuitem', { name: 'Open local folder…' })).toBeTruthy()
@@ -5,6 +5,7 @@ import type {
  SessionListState, WorkspaceId, WorkspaceListState, WorkspaceView,
 } from '@deepseek-ai/dsh-client-runtime/client'
 import { WorkspaceCreateError } from '@deepseek-ai/dsh-client-runtime/client'
+import type { DirectoryFlowOwnerProps } from '../src/client/contract/slots.ts'
 import { WorkspacePicker } from '../src/client/WorkspacePicker.tsx'

 afterEach(cleanup)
@@ -35,15 +36,29 @@ function anchor(): { current: HTMLElement } {
  return { current: element }
 }

+/**
+ * Probe occupant of the directory-flow hole: records the latest owner
+ * conversation so tests drive onPicked/onCancel/onError like a composed flow
+ * package would, and renders a marker element while the flow is open.
+ */
+function flowProbe() {
+  const probe: { owner: DirectoryFlowOwnerProps | undefined } = { owner: undefined }
+  const renderSlot = ((_name: string, owner: DirectoryFlowOwnerProps) => {
+    probe.owner = owner
+    return owner.open ? <div data-testid="directory-flow" data-busy={owner.busy} /> : null
+  }) as never
+  return { probe, renderSlot }
+}
+
 function mount(
  items: readonly WorkspaceView[] = [workspace('alpha', 'Alpha')],
  createWorkspace = vi.fn(),
-  pickDirectory = vi.fn(async () => null as string | null),
-  directoryPickerKind = vi.fn(async () => 'native'),
+  hasDirectoryFlow: () => boolean = () => true,
 ) {
  const onPick = vi.fn()
  const onClose = vi.fn()
  const anchorRef = anchor()
+  const { probe, renderSlot } = flowProbe()
  const renderPicker = (nextItems: readonly WorkspaceView[]) => (
    <WorkspacePicker
      open
@@ -53,23 +68,21 @@ function mount(
      onPick={onPick}
      onClose={onClose}
      createWorkspace={createWorkspace}
-      pickDirectory={pickDirectory}
-      directoryPickerKind={directoryPickerKind}
+      hasDirectoryFlow={hasDirectoryFlow}
+      renderSlot={renderSlot}
    />
  )
  const view = render(
    renderPicker(items),
  )
  return {
-    view, onPick, onClose, createWorkspace, pickDirectory, directoryPickerKind,
+    view, onPick, onClose, createWorkspace, probe,
    rerenderItems: (nextItems: readonly WorkspaceView[]) => { view.rerender(renderPicker(nextItems)) },
  }
 }

-// findByRole, not getByRole: the folder entry renders only after the advertised
-// picker kind resolves, one microtask after the menu opens.
-async function chooseItem(name: 'Open local folder…' | 'Create a new workspace'): Promise<void> {
-  fireEvent.click(await screen.findByRole('menuitem', { name }))
+function chooseItem(name: 'Open local folder…' | 'Create a new workspace'): void {
+  fireEvent.click(screen.getByRole('menuitem', { name }))
 }

 describe('WorkspacePicker', () => {
@@ -83,7 +96,7 @@ describe('WorkspacePicker', () => {
    const created = workspace('new', 'New')
    const createWorkspace = vi.fn(async () => created)
    const b = mount([], createWorkspace)
-    await chooseItem('Create a new workspace')
+    chooseItem('Create a new workspace')
    const input = screen.getByLabelText('New workspace name')
    fireEvent.change(input, { target: { value: 'project-one' } })
    fireEvent.click(screen.getByRole('button', { name: 'Create workspace' }))
@@ -91,78 +104,84 @@ describe('WorkspacePicker', () => {
    await waitFor(() => { expect(b.onPick).toHaveBeenCalledWith(created.workspaceId) })
  })

-  it('opens a native directory picker, adopts its path, and selects the returned Workspace', async () => {
+  it('opens the composed directory flow, adopts its picked path, and selects the returned Workspace', async () => {
    const created = { ...workspace('adopted'), path: '/tmp/project', title: 'project' }
    const createWorkspace = vi.fn(async () => created)
-    const pickDirectory = vi.fn(async () => '/tmp/project')
-    const b = mount([], createWorkspace, pickDirectory)
-    await chooseItem('Open local folder…')
-    expect(pickDirectory).toHaveBeenCalledOnce()
-    await waitFor(() => { expect(createWorkspace).toHaveBeenCalledWith({ path: '/tmp/project' }) })
+    const b = mount([], createWorkspace)
+    expect(screen.queryByTestId('directory-flow')).toBeNull()
+    chooseItem('Open local folder…')
+    expect(b.onClose).toHaveBeenCalled()
+    expect(screen.getByTestId('directory-flow')).toBeTruthy()
+    await act(async () => { b.probe.owner!.onPicked('/tmp/project') })
    expect(createWorkspace).toHaveBeenCalledWith({ path: '/tmp/project' })
    await waitFor(() => { expect(b.onPick).toHaveBeenCalledWith(created.workspaceId) })
+    // Successful adoption withdraws the flow request.
+    expect(screen.queryByTestId('directory-flow')).toBeNull()
  })

-  it('treats native picker cancellation as a silent no-op', async () => {
-    const b = mount([], vi.fn(), vi.fn(async () => null))
-    await chooseItem('Open local folder…')
-    await waitFor(() => { expect(b.pickDirectory).toHaveBeenCalledOnce() })
+  it('treats flow cancellation as a silent no-op', () => {
+    const b = mount([])
+    chooseItem('Open local folder…')
+    act(() => { b.probe.owner!.onCancel() })
+    expect(screen.queryByTestId('directory-flow')).toBeNull()
    expect(b.createWorkspace).not.toHaveBeenCalled()
    expect(b.onPick).not.toHaveBeenCalled()
    expect(screen.queryByRole('dialog')).toBeNull()
  })

-  it('shows a name conflict and retries through the native picker', async () => {
-    const pickDirectory = vi.fn()
-      .mockResolvedValueOnce('/one/project')
-      .mockResolvedValueOnce(null)
+  it('shows a name conflict and retries by reopening the flow', async () => {
    const createWorkspace = vi.fn(async () => {
      throw new WorkspaceCreateError({
        code: 'workspace-name-conflict', message: 'project already exists', details: { name: 'project' },
      })
    })
-    const b = mount([], createWorkspace, pickDirectory)
-    await chooseItem('Open local folder…')
+    const b = mount([], createWorkspace)
+    chooseItem('Open local folder…')
+    await act(async () => { b.probe.owner!.onPicked('/one/project') })
    await waitFor(() => {
      expect(screen.getByRole('dialog', { name: 'A workspace with this name already exists' })).toBeTruthy()
    })
    expect(screen.getByRole('alert').textContent).toBe('Choose a folder with a different name.')
+    // The failed adoption withdrew the flow; Choose again reopens it.
+    expect(b.probe.owner!.open).toBe(false)
    fireEvent.click(screen.getByRole('button', { name: 'Choose again' }))
-    await waitFor(() => { expect(pickDirectory).toHaveBeenCalledTimes(2) })
+    expect(b.probe.owner!.open).toBe(true)
    expect(b.onPick).not.toHaveBeenCalled()
  })

-  it('disables the folder action while the native picker is already open', async () => {
-    let resolve!: (path: string | null) => void
-    const pending = new Promise<string | null>((settle) => { resolve = settle })
-    const b = mount([], vi.fn(), vi.fn(() => pending))
-    await chooseItem('Open local folder…')
+  it('disables the create actions and reports busy to the flow while adopting', async () => {
+    let resolve!: (workspace: WorkspaceView) => void
+    const pending = new Promise<WorkspaceView>((settle) => { resolve = settle })
+    const created = workspace('adopted')
+    const b = mount([], vi.fn(() => pending))
+    chooseItem('Open local folder…')
+    act(() => { b.probe.owner!.onPicked('/tmp/project') })
+    expect(b.probe.owner!.busy).toBe(true)
    expect(screen.getByRole<HTMLButtonElement>('menuitem', { name: 'Open local folder…' }).disabled).toBe(true)
    expect(screen.getByRole<HTMLButtonElement>('menuitem', { name: 'Create a new workspace' }).disabled).toBe(true)
-    fireEvent.click(screen.getByRole('menuitem', { name: 'Open local folder…' }))
-    expect(b.pickDirectory).toHaveBeenCalledTimes(1)
-    await act(async () => { resolve(null); await pending })
+    await act(async () => { resolve(created); await pending })
+    expect(b.probe.owner!.busy).toBe(false)
  })

-  it('reports non-Error native picker failures', async () => {
-    const b = mount([], vi.fn(), vi.fn(async () => { throw 'picker unavailable' }))
-    await chooseItem('Open local folder…')
-    await waitFor(() => {
-      expect(screen.getByRole('alert').textContent).toBe('picker unavailable')
-    })
+  it('shows the flow-reported failure in the folder-error surface', () => {
+    const b = mount([])
+    chooseItem('Open local folder…')
+    act(() => { b.probe.owner!.onError('no chooser installed') })
+    expect(screen.getByRole('alert').textContent).toBe('no chooser installed')
+    expect(screen.queryByTestId('directory-flow')).toBeNull()
    expect(b.createWorkspace).not.toHaveBeenCalled()
  })

-  it('closes a creation modal when the user cancels', async () => {
+  it('closes a creation modal when the user cancels', () => {
    mount([])
-    await chooseItem('Create a new workspace')
+    chooseItem('Create a new workspace')
    fireEvent.click(screen.getByRole('button', { name: 'Cancel' }))
    expect(screen.queryByRole('dialog')).toBeNull()
  })

-  it('blocks a create-new name already present in the Workspace list', async () => {
+  it('blocks a create-new name already present in the Workspace list', () => {
    const b = mount([workspace('alpha', 'Alpha')])
-    await chooseItem('Create a new workspace')
+    chooseItem('Create a new workspace')
    fireEvent.change(screen.getByLabelText('New workspace name'), { target: { value: ' Alpha ' } })
    expect(screen.getByRole('alert').textContent).toBe('A workspace named “Alpha” already exists.')
    expect(screen.getByRole<HTMLButtonElement>('button', { name: 'Create workspace' }).disabled).toBe(true)
@@ -175,7 +194,7 @@ describe('WorkspacePicker', () => {
    const pending = new Promise<WorkspaceView>((settle) => { resolve = settle })
    const created = workspace('fresh', 'same-name')
    const b = mount([], vi.fn(() => pending))
-    await chooseItem('Create a new workspace')
+    chooseItem('Create a new workspace')
    fireEvent.change(screen.getByLabelText('New workspace name'), { target: { value: 'same-name' } })
    fireEvent.click(screen.getByRole('button', { name: 'Create workspace' }))

@@ -191,7 +210,7 @@ describe('WorkspacePicker', () => {
    const pending = new Promise<WorkspaceView>((_resolve, rejectPromise) => { reject = rejectPromise })
    const createWorkspace = vi.fn(() => pending)
    const b = mount([], createWorkspace)
-    await chooseItem('Create a new workspace')
+    chooseItem('Create a new workspace')
    const input = screen.getByLabelText('New workspace name')
    fireEvent.keyDown(input, { key: 'ArrowRight' })
    fireEvent.change(input, { target: { value: 'broken' } })
@@ -208,7 +227,7 @@ describe('WorkspacePicker', () => {

  it('reports non-Error creation failures', async () => {
    const b = mount([], vi.fn(async () => { throw 'permission denied' }))
-    await chooseItem('Create a new workspace')
+    chooseItem('Create a new workspace')
    // The name field starts empty (no prefill); a name is required to submit.
    fireEvent.change(screen.getByLabelText('New workspace name'), { target: { value: 'broken' } })
    fireEvent.click(screen.getByRole('button', { name: 'Create workspace' }))
@@ -219,11 +238,12 @@ describe('WorkspacePicker', () => {
  })

  it('waits to show its menu until an optional anchor is available', () => {
+    const { renderSlot } = flowProbe()
    render(
      <WorkspacePicker
        open useSessions={hook(sessions)} useWorkspaces={hook(workspaceState([]))}
-        onPick={vi.fn()} onClose={vi.fn()} createWorkspace={vi.fn()} pickDirectory={vi.fn()}
-        directoryPickerKind={vi.fn(async () => 'native')}
+        onPick={vi.fn()} onClose={vi.fn()} createWorkspace={vi.fn()}
+        hasDirectoryFlow={() => true} renderSlot={renderSlot}
      />,
    )
    expect(screen.queryByRole('menu')).toBeNull()
@@ -233,101 +253,31 @@ describe('WorkspacePicker', () => {
    const state: WorkspaceListState = {
      ...workspaceState([]), phase: 'pending', state: 'loading', baselinesReady: false,
    }
+    const { renderSlot } = flowProbe()
    render(
      <WorkspacePicker
        open anchorRef={anchor()} useSessions={hook(sessions)} useWorkspaces={hook(state)}
-        onPick={vi.fn()} onClose={vi.fn()} createWorkspace={vi.fn()} pickDirectory={vi.fn()}
-        directoryPickerKind={vi.fn(async () => 'native')}
+        onPick={vi.fn()} onClose={vi.fn()} createWorkspace={vi.fn()}
+        hasDirectoryFlow={() => true} renderSlot={renderSlot}
      />,
    )
    expect(screen.getByRole('status').textContent).toBe('Loading workspaces…')
  })

-  it('hides the folder affordance unless the Host advertises the dialog interaction', async () => {
-    const b = mount([], vi.fn(), vi.fn(async () => null), vi.fn(async () => 'browse'))
-    await screen.findByRole('menuitem', { name: 'Create a new workspace' })
-    await waitFor(() => { expect(b.directoryPickerKind).toHaveBeenCalled() })
+  it('hides the folder entry while the directory-flow hole is empty', () => {
+    mount([], vi.fn(), () => false)
+    expect(screen.getByRole('menuitem', { name: 'Create a new workspace' })).toBeTruthy()
    expect(screen.queryByRole('menuitem', { name: 'Open local folder…' })).toBeNull()
  })

-  it('hides the folder affordance when the Host cannot answer describe', async () => {
-    const b = mount([], vi.fn(), vi.fn(async () => null), vi.fn(async () => {
-      throw new Error('host unreachable')
-    }))
-    await screen.findByRole('menuitem', { name: 'Create a new workspace' })
-    await waitFor(() => { expect(b.directoryPickerKind).toHaveBeenCalled() })
+  it('shows the folder entry once the hole reports an occupant on a later render', () => {
+    let occupied = false
+    const b = mount([], vi.fn(), () => occupied)
    expect(screen.queryByRole('menuitem', { name: 'Open local folder…' })).toBeNull()
-  })
-
-  it('does not read the picker kind while the flow is closed', () => {
-    const directoryPickerKind = vi.fn(async () => 'native')
-    render(
-      <WorkspacePicker
-        open={false} anchorRef={anchor()} useSessions={hook(sessions)} useWorkspaces={hook(workspaceState([]))}
-        onPick={vi.fn()} onClose={vi.fn()} createWorkspace={vi.fn()} pickDirectory={vi.fn()}
-        directoryPickerKind={directoryPickerKind}
-      />,
-    )
-    expect(directoryPickerKind).not.toHaveBeenCalled()
-  })
-
-  /** Render the picker with an owner-controlled `open` and a scripted kind read. */
-  function togglable(directoryPickerKind: () => Promise<string>) {
-    const anchorRef = anchor()
-    const props = (open: boolean) => (
-      <WorkspacePicker
-        open={open} anchorRef={anchorRef} useSessions={hook(sessions)} useWorkspaces={hook(workspaceState([]))}
-        onPick={vi.fn()} onClose={vi.fn()} createWorkspace={vi.fn()} pickDirectory={vi.fn()}
-        directoryPickerKind={directoryPickerKind}
-      />
-    )
-    const view = render(props(true))
-    return { setOpen: (open: boolean) => { view.rerender(props(open)) } }
-  }
-
-  it('discards a kind settlement from a superseded flow open', async () => {
-    let resolveFirst!: (kind: string) => void
-    const first = new Promise<string>((settle) => { resolveFirst = settle })
-    const directoryPickerKind = vi.fn<() => Promise<string>>()
-      .mockImplementationOnce(() => first)
-      .mockImplementation(async () => 'browse')
-    const t = togglable(directoryPickerKind)
-    // Close while the first read is in flight, then let it answer 'native':
-    // the settlement is stale and must not leak into the next open.
-    t.setOpen(false)
-    await act(async () => { resolveFirst('native') })
-    t.setOpen(true)
-    await screen.findByRole('menuitem', { name: 'Create a new workspace' })
-    await waitFor(() => { expect(directoryPickerKind).toHaveBeenCalledTimes(2) })
-    expect(screen.queryByRole('menuitem', { name: 'Open local folder…' })).toBeNull()
-  })
-
-  it('clears the advertised kind on close so a reopen cannot paint the previous host entry', async () => {
-    const directoryPickerKind = vi.fn<() => Promise<string>>()
-      .mockImplementationOnce(async () => 'native')
-      // The reopened read never settles: the assertion below sees the paint
-      // that precedes any fresh answer.
-      .mockImplementation(() => new Promise<string>(() => {}))
-    const t = togglable(directoryPickerKind)
-    await screen.findByRole('menuitem', { name: 'Open local folder…' })
-    t.setOpen(false)
-    t.setOpen(true)
-    await screen.findByRole('menuitem', { name: 'Create a new workspace' })
-    expect(screen.queryByRole('menuitem', { name: 'Open local folder…' })).toBeNull()
-  })
-
-  it('discards a stale describe failure after a newer open already answered', async () => {
-    let rejectFirst!: (reason: Error) => void
-    const first = new Promise<string>((_settle, reject) => { rejectFirst = reject })
-    const directoryPickerKind = vi.fn<() => Promise<string>>()
-      .mockImplementationOnce(() => first)
-      .mockImplementation(async () => 'native')
-    const t = togglable(directoryPickerKind)
-    t.setOpen(false)
-    t.setOpen(true)
-    await screen.findByRole('menuitem', { name: 'Open local folder…' })
-    // The superseded read failing late must not hide the freshly shown entry.
-    await act(async () => { rejectFirst(new Error('late loss')); await first.catch(() => {}) })
+    // A flow package activating after the first paint is observed on the
+    // next render — the same cadence as reopening the menu.
+    occupied = true
+    b.rerenderItems([])
    expect(screen.getByRole('menuitem', { name: 'Open local folder…' })).toBeTruthy()
  })
 })
@@ -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/host/README.md
-README.md: 0810be58fc773a241528656d7f6e826e9c3aabda
-README.zh.md: f9133eee8498594d913b2fe0814ac51d712b678d
+README.md: 7df0ecc4a362be1149188d133233307b1fc48c8a
+README.zh.md: 90d5ea2b0947d2cff9ba06e89b6225b39dad7fce
@@ -9,7 +9,7 @@ The host side of the dsh web GUI: the API gateway every client shape shares, and
 | `apiproxy/` | The shared API gateway: the zero-Node TS wire contract (`src/api/`), the fetch carrier pair (`toFetchHandler` host-side, `AbstractApiClient` client-side), and the host implementation over `ctx.agents`/`ctx.workspace` | `ctx.apiProxy` |
 | `webserver/` | Plain HTTP route-registration carrier: `node:http` server listening on activation; routes register as named `exact`/`prefix` handlers | `ctx.httpServer` |
 | `directory-picker/` | Workspace-directory picking seam: discriminated `native`/`browse` capability the gateway's picker RPCs delegate to | `ctx.directoryPicker` |
-| `directory-picker-native/` | Native-OS-chooser backend (osascript / PowerShell / Zenity+KDialog); host-display only | (registers `ctx.directoryPicker`) |
+| `directory-picker-native/` | Dual-face native interaction: OS-chooser backend (osascript / PowerShell / Zenity+KDialog, host-display only) + the browser half filling ui-workspace's directory-flow slots | (registers `ctx.directoryPicker`) |
 | `directory-picker-browse/` | In-app browsing backend: listing/creation primitives over Node stdlib; remote-capable | (registers `ctx.directoryPicker`) |

 `apiproxy` is transport-agnostic by design — it registers no routes; carriers wrap `ctx.apiProxy` themselves. The HTTP carrier route (with its `/api` browser-trust fence) is mounted by [`client/connection`](../client/connection/README.md)'s node half, which is why that package lives in the client group: it owns both ends of the wire.
@@ -9,7 +9,7 @@ dsh web GUI 的宿主侧：所有客户端形态共用的 API 网关，以及承
 | `apiproxy/` | 共享 API 网关：零 Node 依赖的 TS 协议契约（`src/api/`）、fetch 载体对（宿主侧 `toFetchHandler`、客户端侧 `AbstractApiClient`），以及基于 `ctx.agents`／`ctx.workspace` 的宿主实现 | `ctx.apiProxy` |
 | `webserver/` | 纯 HTTP 路由注册载体：激活即监听的 `node:http` 服务器；路由以命名的 `exact`／`prefix` 处理器注册 | `ctx.httpServer` |
 | `directory-picker/` | 工作区目录选择 seam：网关的 picker RPC 委托的可辨识 `native`／`browse` 能力 | `ctx.directoryPicker` |
-| `directory-picker-native/` | 原生 OS 选择器后端（osascript／PowerShell／Zenity+KDialog）；仅宿主屏幕可用 | （注册 `ctx.directoryPicker`） |
+| `directory-picker-native/` | 双面原生交互：OS 选择器后端（osascript／PowerShell／Zenity+KDialog，仅宿主屏幕可用）+ 填入 ui-workspace 目录流 slot 的 browser half | （注册 `ctx.directoryPicker`） |
 | `directory-picker-browse/` | 应用内浏览后端：基于 Node 标准库的列举／创建原语；支持远程 | （注册 `ctx.directoryPicker`） |

 `apiproxy` 在设计上与传输方式无关——它不注册任何路由；载体自行包装 `ctx.apiProxy`。HTTP 载体路由（连同其 `/api` 浏览器信任栅栏）由 [`client/connection`](../client/connection/README.md) 的 node 半侧挂载，这正是该包住在 client 组的原因：它拥有这条线的两端。
@@ -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/host/apiproxy/README.md
-README.md: 3639722ab25826af8f7a0721f22d244f78b4210b
-README.zh.md: 3ac81fb412d4e4caf192953bc7a7c846a1d29965
+README.md: ca4471454f5be5d3fcba38ce665d4fb3fbd85e74
+README.zh.md: 953539e1198a52b2bf7cdd9ca1b0d263cc2ae6f9
@@ -18,7 +18,7 @@ Session model routing is a session-domain contract. `session.models` returns the

 Workspace and Session lists are separate reconnect baselines. `workspace.create` creates a unique name or adopts an existing directory, `workspace.delete` removes only the Workspace registration, `session.create` accepts an optional preallocated Session id, and `host/workspace-changed`, `host/workspace-removed`, plus `host/session-added` carry committed increments in either arrival order. Registration deletion preserves the directory and session logs; its Sessions remain in `session.list` and become Ungrouped. `SessionSummary.blank` and the `host/session-added` frame carry the derived zero-events bit: clients hide blank sessions and reuse them per workspace, flip blank on the first `host/session-status(running:true)`, and treat `session.list` as the reconnect authority; cold summaries are never blank because lazy persistence keeps never-appended sessions out of `list()`.

-Directory picking delegates to the composed `ctx.directoryPicker` backend ([the directory-picker seam](../directory-picker/README.md)); `host.describe.directoryPicker` advertises the capability kind the client renders for, and a method called outside the advertised kind fails with `directory-picker-unavailable`. Under `native`, `host.pickDirectory` opens one native chooser and returns its selected path (`null` on cancel); this user-paced method is the sole unary call exempt from the default 30-second timeout, and caller/connection aborts still propagate to the native process. Under `browse`, `host.listDirectory` returns one name-sorted directory level with breadcrumb ancestry, a `home` anchor, and host-owned `hidden` flags (absent path = home directory), and `host.createDirectory` creates one validated child segment; the backend's typed failures map 1:1 onto the `directory-unreadable`/`directory-exists`/`directory-create-failed` codes. The browser carrier's prefix-wide trust fence (dsh-client-connection) covers all of these like every other `/api` request.
+Directory picking delegates to the composed `ctx.directoryPicker` backend ([the directory-picker seam](../directory-picker/README.md)); a method called outside the composed capability's kind fails with `directory-picker-unavailable` (the client needs no advertisement — the composed picker package's own client half renders the matching interaction). Under `native`, `host.pickDirectory` opens one native chooser and returns its selected path (`null` on cancel); this user-paced method is the sole unary call exempt from the default 30-second timeout, and caller/connection aborts still propagate to the native process. Under `browse`, `host.listDirectory` returns one name-sorted directory level with breadcrumb ancestry, a `home` anchor, and host-owned `hidden` flags (absent path = home directory), and `host.createDirectory` creates one validated child segment; the backend's typed failures map 1:1 onto the `directory-unreadable`/`directory-exists`/`directory-create-failed` codes. The browser carrier's prefix-wide trust fence (dsh-client-connection) covers all of these like every other `/api` request.

 `host.openPath` opens a filesystem path with the operating system's default application (`open` on macOS, `Invoke-Item` on Windows, `xdg-open` on Linux). The opener is injectable for tests. The browser carrier applies the same loopback, same-origin restriction as `host.pickDirectory`.

@@ -18,7 +18,7 @@

 Workspace 列表与 Session 列表是相互独立的重连基线。`workspace.create` 会创建唯一名称或接纳现有目录，`workspace.delete` 只移除 Workspace 注册记录，`session.create` 接受可选的预分配 Session id，`host/workspace-changed`、`host/workspace-removed` 与 `host/session-added` 则以任意到达顺序携带已提交的增量。删除注册记录会保留目录和会话日志；相关 Session 仍留在 `session.list` 中，并进入 Ungrouped。`SessionSummary.blank` 与 `host/session-added` 帧携带派生的零事件位：客户端隐藏空白会话并按 workspace 复用它们，在首个 `host/session-status(running:true)` 时翻转 blank，并以 `session.list` 作为重连权威；冷会话摘要永远不是空白：惰性持久化让从未追加过事件的会话根本不出现在 `list()` 中。

-目录选择委托给组合的 `ctx.directoryPicker` 后端（[目录选择 seam](../directory-picker/README.md)）；`host.describe.directoryPicker` 广播客户端应按其渲染的能力 kind，调用广播之外的方法会以 `directory-picker-unavailable` 失败。在 `native` 下，`host.pickDirectory` 打开一个原生选择器并返回选中路径（取消为 `null`）；该方法需等待用户完成操作，是唯一不受默认 30 秒超时限制的一元调用，调用方与连接的中止仍会传播至原生进程。在 `browse` 下，`host.listDirectory` 返回一个按名称排序的目录层级，携带面包屑祖先链、`home` 锚点与宿主判定的 `hidden` 标志（不带路径即家目录），`host.createDirectory` 创建一个经校验的子段；后端的类型化失败 1:1 映射为 `directory-unreadable`／`directory-exists`／`directory-create-failed` 错误码。浏览器载体的前缀级信任栅栏（dsh-client-connection）像覆盖其他所有 `/api` 请求一样覆盖上述全部方法。
+目录选择委托给组合的 `ctx.directoryPicker` 后端（[目录选择 seam](../directory-picker/README.md)）；调用组合能力 kind 之外的方法会以 `directory-picker-unavailable` 失败（客户端不需要广播——组合的选择器包自己的 client half 渲染匹配的交互）。在 `native` 下，`host.pickDirectory` 打开一个原生选择器并返回选中路径（取消为 `null`）；该方法需等待用户完成操作，是唯一不受默认 30 秒超时限制的一元调用，调用方与连接的中止仍会传播至原生进程。在 `browse` 下，`host.listDirectory` 返回一个按名称排序的目录层级，携带面包屑祖先链、`home` 锚点与宿主判定的 `hidden` 标志（不带路径即家目录），`host.createDirectory` 创建一个经校验的子段；后端的类型化失败 1:1 映射为 `directory-unreadable`／`directory-exists`／`directory-create-failed` 错误码。浏览器载体的前缀级信任栅栏（dsh-client-connection）像覆盖其他所有 `/api` 请求一样覆盖上述全部方法。

 `host.openPath` 会用操作系统的默认应用打开一个文件系统路径（macOS 为 `open`，Windows 为 `Invoke-Item`，Linux 为 `xdg-open`）。打开器可在测试中注入。浏览器载体对其施加与 `host.pickDirectory` 相同的回环、同源限制。

@@ -1009,7 +1009,6 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
          provider: defaults.provider,
          model: defaults.model,
          attachedSessions: ctx.agents.list().length,
-          directoryPicker: ctx.directoryPicker.capability().kind,
        }))
      },

@@ -19,7 +19,6 @@ export const hostDescribeValueSchema = z.object({
  attachedSessions: z.number().int().nonnegative(),
  // Open string, not a literal union: unknown kinds must survive the wire so
  // a merge-added capability can advertise (the client hides the affordance).
-  directoryPicker: z.string(),
 }) satisfies z.ZodType<Wire<ResponseValue<'host.describe'>>>

 /** host.pickDirectory request payload (empty object literal). */
@@ -5,18 +5,6 @@

 import type { RpcRequest, RpcResponse } from './rpc.ts'

-/**
- * The composed directory-picker interaction the host serves (mirror of the
- * `ctx.directoryPicker` capability kind): `native` = one OS chooser on
- * the host display (`host.pickDirectory`); `browse` = in-app listing/creation
- * primitives (`host.listDirectory`/`host.createDirectory`). Calling a method
- * outside the advertised kind fails with `directory-picker-unavailable`.
- * The wire preserves kinds beyond the two with methods here (a merge-added
- * capability advertises before its RPCs exist); the client's documented
- * default for a kind it does not recognize is to hide the picking affordance.
- */
-export type DirectoryPickerKind = 'native' | 'browse' | (string & {})
-
 /** One directory row of a listing: a child entry or a breadcrumb ancestor. */
 export interface DirectoryEntry {
  /** Base name shown in a browser row (a root crumb carries its full path). */
@@ -51,7 +39,6 @@ export interface HostApi {
   * applied when a new agent doesn't specify them explicitly, absent when the host configures
   * no explicit default (the adapter falls back internally);
   * attachedSessions = count of currently attached sessions (those with a live agent);
-   * directoryPicker = the composed picker interaction the client renders for.
   */
  describe(request: RpcRequest<{}>): Promise<RpcResponse<{
    version: string
@@ -59,7 +46,6 @@ export interface HostApi {
    provider?: string
    model?: string
    attachedSessions: number
-    directoryPicker: DirectoryPickerKind
  }>>

  /**
@@ -29,7 +29,7 @@ export type {
  HistoryEntry, ModelCatalogFailure, ModelCatalogModel, ModelProviderGroup, ModelReasoning,
  ModelReasoningEffort, ModelTarget, SessionModels, SessionProjectionsBlock, SessionsApi, SessionSummary,
 } from './sessions.ts'
-export type { DirectoryEntry, DirectoryListing, DirectoryPickerKind, HostApi } from './host.ts'
+export type { DirectoryEntry, DirectoryListing, HostApi } from './host.ts'
 export type { WorkspaceApi, WorkspaceId, WorkspaceView } from './workspace.ts'
 export type { CommandsApi, CommandDescriptor } from './commands.ts'
 export type { SkillsApi, SkillEntry } from './skills.ts'
@@ -192,17 +192,14 @@ describe('host.listDirectory / host.createDirectory', () => {
    })
  })

-  it('refuses the browse RPCs under a native composition and advertises the kind in describe', async () => {
+  it('refuses the browse RPCs under a native composition', async () => {
    const { api } = await harness()
-    expect((await api.host.describe(request({}))).result).toMatchObject({ ok: true, value: { directoryPicker: 'native' } })
    expect((await api.host.listDirectory(request({}))).result).toMatchObject({
      ok: false, error: { code: 'directory-picker-unavailable', details: { capability: 'native' } },
    })
    expect((await api.host.createDirectory(request({ path: '/x', name: 'y' }))).result).toMatchObject({
      ok: false, error: { code: 'directory-picker-unavailable', details: { capability: 'native' } },
    })
-    const browse = await harness(undefined, BROWSE_STUB)
-    expect((await browse.api.host.describe(request({}))).result).toMatchObject({ ok: true, value: { directoryPicker: 'browse' } })
  })
 })

@@ -48,7 +48,7 @@ function scriptedApi(overrides: {
      ...overrides.sessions,
    },
    host: {
-      describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0, directoryPicker: 'browse' as const }),
+      describe: r => ok(r, { version: '0-test', cwd: '/t', attachedSessions: 0 }),
      pickDirectory: r => ok(r, { path: null }),
      listDirectory: r => ok(r, { path: '/t', home: '/t', crumbs: [], entries: [] }),
      createDirectory: r => ok(r, { path: '/t/new' }),
@@ -76,7 +76,7 @@ function fakeApi(overrides: Partial<{ muxFrames: MuxFrame[]; hostFrames: HostFra
    },
    host: {
      async describe(request) {
-        return { rpcId: request.rpcId, result: { ok: true, value: { version: 'v', cwd: '/w', attachedSessions: 0, directoryPicker: 'native' as const } } }
+        return { rpcId: request.rpcId, result: { ok: true, value: { version: 'v', cwd: '/w', attachedSessions: 0 } } }
      },
      async pickDirectory(request) {
        return { rpcId: request.rpcId, result: { ok: true, value: { path: null } } }
@@ -218,12 +218,9 @@ describe('sessions domain schemas', () => {
 describe('host domain schemas', () => {
  it('validates describe request/value', () => {
    expect(hostDescribeRequestSchema.parse({})).toEqual({})
-    const value = hostDescribeValueSchema.parse({ version: '1', cwd: '/x', provider: 'p', model: 'm', attachedSessions: 2, directoryPicker: 'native' })
+    const value = hostDescribeValueSchema.parse({ version: '1', cwd: '/x', provider: 'p', model: 'm', attachedSessions: 2 })
    expect(value.attachedSessions).toBe(2)
-    expect(hostDescribeValueSchema.parse({ version: '1', cwd: '/x', attachedSessions: 0, directoryPicker: 'browse' }).provider).toBeUndefined()
-    // A kind beyond the two with methods survives the wire (merge-added
-    // capabilities advertise; the client hides the affordance).
-    expect(hostDescribeValueSchema.parse({ version: '1', cwd: '/x', attachedSessions: 0, directoryPicker: 'other' }).directoryPicker).toBe('other')
+    expect(hostDescribeValueSchema.parse({ version: '1', cwd: '/x', attachedSessions: 0 }).provider).toBeUndefined()
  })

  it('validates the browse listing/creation payloads', () => {
@@ -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/host/directory-picker-native/README.md
-README.md: 8e9d6c7c558a6b33c2a37d504c571fd3eda579bb
-README.zh.md: 68f23698ff0c1a5ee4456a1f121dcf244f09c72b
+README.md: 0b54c651d4f5382021d0f8832ab4f1146b7652c8
+README.zh.md: e5ac2762a691a16a7e6d9d6dd9aefc70a59dcd4f
@@ -2,7 +2,9 @@

 English | [中文](README.zh.md)

-The **native-OS-chooser backend** of the [directory-picker seam](../directory-picker/README.md): `NativeDirectoryPicker` registers `ctx.directoryPicker` with the `native` capability, whose `pick(signal)` opens one native chooser per call and resolves the chosen absolute path (`null` on cancel). Platform tools run without a shell: `osascript` on macOS, an STA PowerShell `FolderBrowserDialog` on Windows, and Zenity with a KDialog fallback on Linux; the caller's abort terminates the native process. Only viable when the operator sits at the host's display — remote deployments compose [`-browse`](../directory-picker-browse/README.md) instead. The command boundary (`DirectoryPickerRunner`) and platform facts are injectable for deterministic tests.
+The **native-OS-chooser backend** of the [directory-picker seam](../directory-picker/README.md): `NativeDirectoryPicker` registers `ctx.directoryPicker` with the `native` capability, whose `pick(signal)` opens one native chooser per call and resolves the chosen absolute path (`null` on cancel). Platform tools run without a shell: `osascript` on macOS, an STA PowerShell `FolderBrowserDialog` on Windows, and Zenity with a KDialog fallback on Linux; the caller's abort terminates the native process. Only viable when the operator sits at the host's display — remote deployments compose [`-browse`](../directory-picker-browse/README.md) instead. The command boundary (`DirectoryPickerRunner`) and platform facts are injectable for deterministic tests. The shared no-shell subprocess runner lives in [`dsh-native-command`](../../util/native-command/README.md).
+
+**Dual-face package**: the browser half (`./client`) registers a renderless flow occupant into [ui-workspace's](../../client/ui-workspace/README.md) two directory-flow holes — each `open` request drives `host.pickDirectory` and reports the one outcome (picked path / cancel / failure) through the hole's owner conversation. One cordis.yml row therefore composes both sides of the native interaction; the client carries no capability-kind branching, and mounting a second flow package fails at load (the holes are `single` kind).

 ## Model Experience

@@ -2,7 +2,9 @@

 [English](README.md) | 中文

-[目录选择 seam](../directory-picker/README.md) 的**原生 OS 选择器后端**：`NativeDirectoryPicker` 以 `native` 能力注册 `ctx.directoryPicker`，其 `pick(signal)` 每次调用打开一个原生选择器并解析出所选绝对路径（取消时为 `null`）。平台工具不经 shell 调用：macOS 使用 `osascript`，Windows 使用以 STA 模式运行的 PowerShell `FolderBrowserDialog`，Linux 使用 Zenity 并以 KDialog 回退；调用方的中止信号会终止原生进程。只有操作者坐在宿主屏幕前时才可用——远程部署应组合 [`-browse`](../directory-picker-browse/README.md)。命令边界（`DirectoryPickerRunner`）与平台事实可注入，便于确定性测试。
+[目录选择 seam](../directory-picker/README.md) 的**原生 OS 选择器后端**：`NativeDirectoryPicker` 以 `native` 能力注册 `ctx.directoryPicker`，其 `pick(signal)` 每次调用打开一个原生选择器并解析出所选绝对路径（取消时为 `null`）。平台工具不经 shell 调用：macOS 使用 `osascript`，Windows 使用以 STA 模式运行的 PowerShell `FolderBrowserDialog`，Linux 使用 Zenity 并以 KDialog 回退；调用方的中止信号会终止原生进程。只有操作者坐在宿主屏幕前时才可用——远程部署应组合 [`-browse`](../directory-picker-browse/README.md)。命令边界（`DirectoryPickerRunner`）与平台事实可注入，便于确定性测试。共享的免 shell 子进程运行器位于 [`dsh-native-command`](../../util/native-command/README.md)。
+
+**双面包**：browser half（`./client`）向 [ui-workspace](../../client/ui-workspace/README.md) 的两个目录流洞注册一个无渲染的流程占用者——每次 `open` 请求驱动 `host.pickDirectory`，并经洞的 owner 会话上报唯一结果（所选路径／取消／失败）。因此一行 cordis.yml 同时组合原生交互的两侧；client 侧不含任何能力 kind 分支，挂载第二个流程包会在加载期失败（洞为 `single` kind）。

 ## 模型体验

@@ -15,12 +15,17 @@
      "types": "./lib/types/invariant.d.ts",
      "default": "./lib/invariant.js"
    },
+    "./client": {
+      "types": "./lib/types/client/index.d.ts",
+      "default": "./lib/client.js"
+    },
    "./src/*": "./src/*",
    "./package.json": "./package.json"
  },
  "files": [
    "lib/index.js",
    "lib/invariant.js",
+    "lib/client.js",
    "lib/types/**/*.d.ts",
    "lib/types/**/*.d.ts.map",
    "src"
@@ -31,11 +36,27 @@
    "@deepseek-ai/dsh-native-command": "workspace:^"
  },
  "peerDependencies": {
+    "@deepseek-ai/dsh-client-runtime": "^0.0.1",
+    "@deepseek-ai/dsh-client-ui-slots": "^0.0.1",
+    "@deepseek-ai/dsh-client-ui-workspace": "^0.0.1",
    "@deepseek-ai/dsh-invariants": "^0.0.1",
-    "cordis": "^4.0.0-rc.7"
+    "cordis": "^4.0.0-rc.7",
+    "react": "^18.2.0"
  },
  "devDependencies": {
+    "@deepseek-ai/dsh-client-runtime": "workspace:^",
+    "@deepseek-ai/dsh-client-ui-slots": "workspace:^",
+    "@deepseek-ai/dsh-client-ui-workspace": "workspace:^",
    "@deepseek-ai/dsh-invariants": "workspace:^",
-    "cordis": "^4.0.0-rc.7"
+    "@types/react": "~18.3.1",
+    "cordis": "^4.0.0-rc.7",
+    "react": "^18.2.0"
+  },
+  "dshClient": {
+    "inject": [
+      "@deepseek-ai/dsh-client-runtime",
+      "@deepseek-ai/dsh-client-ui-workspace"
+    ],
+    "platform": "web"
  }
 }
@@ -0,0 +1,73 @@
+/**
+ * Browser half of the native directory-picker backend: fills ui-workspace's
+ * two directory-flow holes with a renderless occupant that answers each
+ * `open` by driving `host.pickDirectory` (the node half's OS chooser) and
+ * reporting the one outcome — picked path, cancellation, or failure — back
+ * through the owner conversation. Mounting this package therefore composes
+ * both sides of the native interaction with one cordis.yml row; no client
+ * code branches on a capability kind.
+ */
+import { useEffect, useRef } from 'react'
+import type { ReactElement } from 'react'
+import { deferRegistration } from '@deepseek-ai/dsh-client-ui-slots'
+import type { ClientContext } from '@deepseek-ai/dsh-client-runtime/client'
+// Type-only: the SlotMap merge declaring the directory-flow holes and their owner contract.
+import type { DirectoryFlowOwnerProps } from '@deepseek-ai/dsh-client-ui-workspace/client'
+
+/** Injected face: the wire call the flow drives (bound in apply's closure). */
+interface NativeFlowInjected {
+  /** Ask the local Host to open its native single-directory chooser. */
+  pick: () => Promise<string | null>
+}
+
+/**
+ * Renderless flow occupant: each rising `open` edge runs exactly one pick and
+ * reports exactly one outcome; the ref arms once per open so re-renders (and
+ * an adoption keeping `open` true while `busy`) never launch a second
+ * chooser. The owner withdrawing `open` re-arms the next request.
+ * @param props - owner conversation plus the injected pick call.
+ * @returns nothing — the native chooser renders on the host display.
+ */
+export function NativeDirectoryFlow(props: DirectoryFlowOwnerProps & NativeFlowInjected): ReactElement | null {
+  const { open, pick } = props
+  const armed = useRef(false)
+  // Callbacks ride a ref so the settled pick reports through the owner's
+  // latest handlers, not the ones captured when the chooser opened.
+  const outcome = useRef(props)
+  outcome.current = props
+  useEffect(() => {
+    if (!open) {
+      armed.current = false
+      return
+    }
+    if (armed.current) return
+    armed.current = true
+    pick().then(
+      (path) => { if (path === null) outcome.current.onCancel(); else outcome.current.onPicked(path) },
+      (reason: unknown) => { outcome.current.onError(reason instanceof Error ? reason.message : String(reason)) },
+    )
+  }, [open, pick])
+  return null
+}
+
+/** Required services (cordis fiber inject): the slot registry and the wire-facing workspace service. */
+export const inject = ['slots', 'workspaces']
+
+/**
+ * Client plugin body: register the renderless native flow into both
+ * directory-flow holes (declaration-aware deferral — the declaring
+ * ui-workspace entries may activate later, and an HMR collapse re-declares).
+ * @param ctx - client root context.
+ */
+export function apply(ctx: ClientContext): void {
+  const injected = (): NativeFlowInjected => ({ pick: () => ctx.workspaces.pickDirectory() })
+  ctx.effect(() => {
+    const deferred = [
+      deferRegistration(ctx.slots, 'conversation.hero.workspace.directoryFlow', NativeDirectoryFlow, () =>
+        ctx.slots.register({ name: 'conversation.hero.workspace.directoryFlow', inject: injected }, NativeDirectoryFlow)),
+      deferRegistration(ctx.slots, 'sidebar.workspaces.directoryFlow', NativeDirectoryFlow, () =>
+        ctx.slots.register({ name: 'sidebar.workspaces.directoryFlow', inject: injected }, NativeDirectoryFlow)),
+    ]
+    return () => { for (const entry of deferred) entry.dispose() }
+  }, 'directory-picker-native: flow registrations')
+}
@@ -1,4 +1,4 @@
-/** Cross-platform native single-directory chooser behind the dialog backend's capability. */
+/** Cross-platform native single-directory chooser behind the native backend's capability. */

 import { runNativeCommand, type NativeCommandRunner } from '@deepseek-ai/dsh-native-command'

@@ -0,0 +1,123 @@
+// @vitest-environment jsdom
+import { Context } from 'cordis'
+import { describe, expect, it, vi } from 'vitest'
+import { act, cleanup, render } from '@testing-library/react'
+import { afterEach } from 'vitest'
+import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
+import type { DirectoryFlowOwnerProps } from '@deepseek-ai/dsh-client-ui-workspace/client'
+import { apply, inject, NativeDirectoryFlow } from '../src/client/index.ts'
+
+afterEach(cleanup)
+
+const HOLES = ['conversation.hero.workspace.directoryFlow', 'sidebar.workspaces.directoryFlow'] as const
+
+async function bench() {
+  const ctx = new Context()
+  await ctx.plugin(SlotsService).await()
+  const pickDirectory = vi.fn(async (): Promise<string | null> => '/tmp/picked')
+  ctx.provide('workspaces', { pickDirectory } as never)
+  const slots = ctx.get('slots') as SlotsService
+  const declare = () => slots.register({
+    name: 'root',
+    children: Object.fromEntries(HOLES.map(name => [name, { kind: 'single', scope: 'root' }])),
+  } as never, () => null)
+  return { ctx, slots, pickDirectory, declare }
+}
+
+function owner(overrides: Partial<DirectoryFlowOwnerProps> = {}): DirectoryFlowOwnerProps {
+  return {
+    open: true, busy: false,
+    onPicked: vi.fn(), onCancel: vi.fn(), onError: vi.fn(),
+    ...overrides,
+  }
+}
+
+describe('directory-picker-native client half', () => {
+  it('declares the services it drives', () => {
+    expect(inject).toEqual(['slots', 'workspaces'])
+  })
+
+  it('fills both directory-flow holes for declarations before or after apply, and leaves with its fiber', async () => {
+    const before = await bench()
+    before.declare()
+    const fiber = before.ctx.plugin({ inject: [...inject], apply })
+    await fiber.await()
+    for (const hole of HOLES) expect(before.slots.entries(hole)).toHaveLength(1)
+    // Registry-contribution disposal proof: the fiber going down empties the holes.
+    await fiber.dispose()
+    for (const hole of HOLES) expect(before.slots.entries(hole)).toHaveLength(0)
+
+    const after = await bench()
+    await after.ctx.plugin({ inject: [...inject], apply }).await()
+    for (const hole of HOLES) expect(after.slots.entries(hole)).toHaveLength(0)
+    after.declare()
+    await Promise.resolve()
+    for (const hole of HOLES) expect(after.slots.entries(hole)).toHaveLength(1)
+  })
+
+  it('rejects a second flow occupant at load (single-kind hole)', async () => {
+    const b = await bench()
+    b.declare()
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    expect(() => b.slots.register({ name: HOLES[0] } as never, () => null))
+      .toThrow(/already has a registration/)
+  })
+
+  it('drives the injected pick through the hole entry and reports the picked path', async () => {
+    const b = await bench()
+    b.declare()
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    const entry = b.slots.entries(HOLES[0])[0]!
+    const injected = (entry.inject as () => { pick: () => Promise<string | null> })()
+    await expect(injected.pick()).resolves.toBe('/tmp/picked')
+    expect(b.pickDirectory).toHaveBeenCalledOnce()
+  })
+
+  it('runs one pick per open edge and reports the path to the latest onPicked', async () => {
+    let resolve!: (path: string | null) => void
+    const pick = vi.fn(() => new Promise<string | null>((settle) => { resolve = settle }))
+    const first = owner()
+    const view = render(<NativeDirectoryFlow {...first} pick={pick} />)
+    expect(pick).toHaveBeenCalledOnce()
+    // Re-renders while open (busy flips, handler identity changes) must not relaunch the chooser.
+    const second = owner()
+    view.rerender(<NativeDirectoryFlow {...second} busy pick={pick} />)
+    expect(pick).toHaveBeenCalledOnce()
+    await act(async () => { resolve('/tmp/project') })
+    expect(second.onPicked).toHaveBeenCalledWith('/tmp/project')
+    expect(first.onPicked).not.toHaveBeenCalled()
+  })
+
+  it('reports null as cancellation and re-arms after the owner withdraws open', async () => {
+    const pick = vi.fn(async () => null as string | null)
+    const props = owner()
+    const view = render(<NativeDirectoryFlow {...props} pick={pick} />)
+    await act(async () => {})
+    expect(props.onCancel).toHaveBeenCalledOnce()
+    expect(props.onPicked).not.toHaveBeenCalled()
+    // Withdraw and reopen: a fresh request runs a fresh pick.
+    view.rerender(<NativeDirectoryFlow {...props} open={false} pick={pick} />)
+    view.rerender(<NativeDirectoryFlow {...props} pick={pick} />)
+    await act(async () => {})
+    expect(pick).toHaveBeenCalledTimes(2)
+  })
+
+  it('folds pick failures into onError messages', async () => {
+    const props = owner()
+    render(<NativeDirectoryFlow {...props} pick={vi.fn(async () => { throw new Error('no chooser installed') })} />)
+    await act(async () => {})
+    expect(props.onError).toHaveBeenCalledWith('no chooser installed')
+
+    const nonError = owner()
+    render(<NativeDirectoryFlow {...nonError} pick={vi.fn(async () => { throw 'denied' })} />)
+    await act(async () => {})
+    expect(nonError.onError).toHaveBeenCalledWith('denied')
+  })
+
+  it('renders nothing while closed and while open', () => {
+    const closed = render(<NativeDirectoryFlow {...owner({ open: false })} pick={vi.fn(async () => null)} />)
+    expect(closed.container.innerHTML).toBe('')
+    const opened = render(<NativeDirectoryFlow {...owner()} pick={vi.fn(async () => null)} />)
+    expect(opened.container.innerHTML).toBe('')
+  })
+})
@@ -1,19 +1,16 @@
 {
-  "extends": "../../../tsconfig.base.json",
+  "extends": "../../../tsconfig.base.client.json",
  "compilerOptions": {
    "rootDir": "src",
-    "outDir": "lib/types"
+    "outDir": "lib/types",
+    "types": [
+      "node"
+    ]
  },
  "include": [
    "src"
  ],
  "references": [
-    {
-      "path": "../../../vendor/cosmokit"
-    },
-    {
-      "path": "../../../vendor/cordis"
-    },
    {
      "path": "../directory-picker"
    },
@@ -22,6 +19,15 @@
    },
    {
      "path": "../../util/native-command"
+    },
+    {
+      "path": "../../client/ui-slots"
+    },
+    {
+      "path": "../../client/runtime"
+    },
+    {
+      "path": "../../client/ui-workspace"
    }
  ]
 }
@@ -0,0 +1,3 @@
+import { clientBundle } from '../../client/tsdown.client.ts'
+
+export default clientBundle('@deepseek-ai/dsh-host-directory-picker-native', ['lib/types/index.js', 'lib/types/invariant.js'])
@@ -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/host/directory-picker/README.md
-README.md: dcac8903522d53a8dd5fd346f124071f0f24b38e
-README.zh.md: 5b7fc15513bf19722bd71bcbb30c6d187d6a71f5
+README.md: 8ef8889c875f5b1d07c015ddef819591041c8d7f
+README.zh.md: 8aefffa7b29a47205ea42d0d1df742d1e1b2502d
@@ -2,7 +2,7 @@

 English | [中文](README.zh.md)

-The **workspace-directory picking seam** for the web-GUI host: an abstract `DirectoryPicker` service (`ctx.directoryPicker`) whose single contract method `capability()` returns a discriminated capability describing how an operator selects a directory. Backends differ in interaction shape, not just mechanism, so the seam models the shapes explicitly instead of one method set: `{ kind: 'native', pick(signal) }` opens one native OS chooser on the host display ([`-native`](../directory-picker-native/README.md)); `{ kind: 'browse', list(path?), createDirectory(path, name) }` serves listing/creation primitives an in-app browser drives, which works for remote clients no OS chooser can reach ([`-browse`](../directory-picker-browse/README.md)). Consumers switch on `capability().kind`; the union derives from the merge-extensible `DirectoryPickerCapabilities` map (a new backend declaration-merges its shape there), and the documented default for an unknown kind is to hide the picking affordance rather than fail. The capability object must be stable for the service lifetime.
+The **workspace-directory picking seam** for the web-GUI host: an abstract `DirectoryPicker` service (`ctx.directoryPicker`) whose single contract method `capability()` returns a discriminated capability describing how an operator selects a directory. Backends differ in interaction shape, not just mechanism, so the seam models the shapes explicitly instead of one method set: `{ kind: 'native', pick(signal) }` opens one native OS chooser on the host display ([`-native`](../directory-picker-native/README.md)); `{ kind: 'browse', list(path?), createDirectory(path, name) }` serves listing/creation primitives an in-app browser drives, which works for remote clients no OS chooser can reach ([`-browse`](../directory-picker-browse/README.md)). Consumers switch on `capability().kind`; the union derives from the merge-extensible `DirectoryPickerCapabilities` map (a new backend declaration-merges its shape there), and the documented default for an unknown kind is to hide the picking affordance rather than fail. The capability object must be stable for the service lifetime. The client side mirrors the seam without a wire advertisement: each backend package is dual-face, its browser half registering the matching picking interaction into ui-workspace's directory-flow slots — so one composition row swaps both the host capability and the client flow together.

 Browse primitives fail with the typed `DirectoryPickerError` (`directory-unreadable` / `directory-exists` / `directory-create-failed`, each carrying the subject `path`), which the consuming gateway maps 1:1 onto wire error codes. `DirectoryEntry` rows carry a host-owned `hidden` flag (POSIX dot convention) so display policy stays client-side; `DirectoryListing.crumbs` is the ancestor chain from the filesystem root, every crumb a jump target. Design rationale, the `ctx.fs` separation, and the policy decisions live in [the directory-picker capability seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md).

@@ -2,7 +2,7 @@

 [English](README.md) | 中文

-web GUI 宿主的**工作区目录选择 seam**：抽象服务 `DirectoryPicker`（`ctx.directoryPicker`），唯一契约方法 `capability()` 返回一个可辨识能力对象，描述操作者以何种方式选择目录。后端之间的差异在交互形态而不只是机制，因此 seam 显式建模形态而非统一方法集：`{ kind: 'native', pick(signal) }` 在宿主屏幕上打开一个原生 OS 选择器（[`-native`](../directory-picker-native/README.md)）；`{ kind: 'browse', list(path?), createDirectory(path, name) }` 提供应用内浏览器驱动的列举／创建原语，可服务任何 OS 对话框都触及不到的远程客户端（[`-browse`](../directory-picker-browse/README.md)）。消费方按 `capability().kind` 分支；联合类型由可合并扩展的 `DirectoryPickerCapabilities` 映射派生（新后端在其中声明合并自己的形态），未知 kind 的文档化默认行为是隐藏选择入口而非失败。能力对象在服务生命周期内必须保持稳定。
+web GUI 宿主的**工作区目录选择 seam**：抽象服务 `DirectoryPicker`（`ctx.directoryPicker`），唯一契约方法 `capability()` 返回一个可辨识能力对象，描述操作者以何种方式选择目录。后端之间的差异在交互形态而不只是机制，因此 seam 显式建模形态而非统一方法集：`{ kind: 'native', pick(signal) }` 在宿主屏幕上打开一个原生 OS 选择器（[`-native`](../directory-picker-native/README.md)）；`{ kind: 'browse', list(path?), createDirectory(path, name) }` 提供应用内浏览器驱动的列举／创建原语，可服务任何 OS 对话框都触及不到的远程客户端（[`-browse`](../directory-picker-browse/README.md)）。消费方按 `capability().kind` 分支；联合类型由可合并扩展的 `DirectoryPickerCapabilities` 映射派生（新后端在其中声明合并自己的形态），未知 kind 的文档化默认行为是隐藏选择入口而非失败。能力对象在服务生命周期内必须保持稳定。client 侧以镜像方式承接该 seam 而不经 wire 广播：每个后端包都是双面包，其 browser half 把匹配的选取交互注册进 ui-workspace 的目录流 slot——因此一行组合同时切换宿主能力与 client 流程。

 浏览原语以带类型的 `DirectoryPickerError` 失败（`directory-unreadable`／`directory-exists`／`directory-create-failed`，各自携带主体 `path`），消费网关将其 1:1 映射为协议错误码。`DirectoryEntry` 行携带宿主判定的 `hidden` 标志（POSIX 点前缀约定），展示策略留在客户端；`DirectoryListing.crumbs` 是从文件系统根开始的祖先链，每个 crumb 都是跳转目标。设计依据、与 `ctx.fs` 的切分、策略裁决见[目录选择能力 seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md)。

@@ -3,4 +3,4 @@
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/util/native-command/README.md
 README.md: 7fc8b1f4640ef87ada62b6656854feb37080e4e6
-README.zh.md: 7c1cacb06d1d58601cc9e63c2ebd9c5f0ccb8159
+README.zh.md: 4bc66c4047194de03f236fa7591dad88e5c3fb57
@@ -4,7 +4,7 @@

 宿主原生 OS 集成共享的**零依赖免 shell `execFile` 运行器**：一次 `runNativeCommand(command, args, signal)` 调用直接派生可执行文件（绝不拼 shell 字符串），以 utf8 捕获 stdout/stderr，把调用方的 abort 传播为子进程终止，并在 Windows 上隐藏瞬时控制台窗口。失败时以附带退出 `code` 与两路已捕获输出的错误拒绝，调用方无需重跑即可分类（工具缺失、已取消、真实失败）。

-它的两个消费者都是宿主侧原生集成：[`directory-picker-native`](../../host/directory-picker-native/README.zh.md) 后端的 OS 选择器命令，以及网关的按默认应用打开转交（[`dsh-host-apiproxy`](../../host/apiproxy/README.zh.md) 的 `host.openPath`）。`NativeCommandRunner` 类型是这些调用方为确定性测试暴露的可注入命令边界。
+它的两个消费者都是宿主侧原生集成：[`directory-picker-native`](../../host/directory-picker-native/README.md) 后端的 OS 选择器命令，以及网关的按默认应用打开转交（[`dsh-host-apiproxy`](../../host/apiproxy/README.md) 的 `host.openPath`）。`NativeCommandRunner` 类型是这些调用方为确定性测试暴露的可注入命令边界。

 它是**库，不是服务或插件**：没有 `ctx`、不注册任何东西、不持有状态、不发事件。

@@ -2760,12 +2760,27 @@ importers:
        specifier: workspace:^
        version: link:../../util/native-command
    devDependencies:
+      '@deepseek-ai/dsh-client-runtime':
+        specifier: workspace:^
+        version: link:../../client/runtime
+      '@deepseek-ai/dsh-client-ui-slots':
+        specifier: workspace:^
+        version: link:../../client/ui-slots
+      '@deepseek-ai/dsh-client-ui-workspace':
+        specifier: workspace:^
+        version: link:../../client/ui-workspace
      '@deepseek-ai/dsh-invariants':
        specifier: workspace:^
        version: link:../../support/invariants
+      '@types/react':
+        specifier: ~18.3.1
+        version: 18.3.31
      cordis:
        specifier: ^4.0.0-rc.7
        version: 4.0.0-rc.7(@cordisjs/plugin-include@1.0.4)(@cordisjs/plugin-loader@1.0.0-rc.5)
+      react:
+        specifier: ^18.2.0
+        version: 18.3.1

  packages/host/webserver:
    dependencies:
@@ -423,7 +423,7 @@ const SERVICE_ROLES: ServiceRole[] = [
    mode: 'seam',
    implementations: ['directory-picker-native', 'directory-picker-browse'],
    consumers: ['apiproxy'],
-    note: 'Discriminated interaction capability: the native backend opens one OS chooser on the host display, the browse backend serves listing/creation primitives for the in-app browser; the gateway advertises the kind via host.describe.',
+    note: 'Discriminated interaction capability: the native backend opens one OS chooser on the host display, the browse backend serves listing/creation primitives for the in-app browser; each backend is dual-face, its browser half filling ui-workspace directory-flow slots (no wire advertisement).',
  },
  {
    key: 'httpServer',
@@ -19,6 +19,8 @@
    "packages/client/*/src/css-modules.d.ts",
    "packages/client/*/tests/**/*.ts",
    "packages/client/*/tests/**/*.tsx",
+    "packages/host/directory-picker-native/tests/**/*.ts",
+    "packages/host/directory-picker-native/tests/**/*.tsx",
    "packages/client/tsdown.client.ts",
    "scripts/client-bundle-purity.spec.ts"
  ],
@@ -27,6 +29,10 @@
    // smoke policy). webserver has zero workspace deps and no cordis merge,
    // so it cannot drag host-side Context augmentation into this program.
    { "path": "./packages/host/webserver" },
+    // Dual-face host leaf: the node half is the native picking backend, the
+    // browser half registers the picking flow into ui-workspace's slot —
+    // client-side Context merges keep it out of the host program.
+    { "path": "./packages/host/directory-picker-native" },
    { "path": "./packages/client/ui-slots" },
    { "path": "./packages/client/ui-primitives" },
    { "path": "./packages/client/web-react" },
@@ -33,6 +33,7 @@
  ],
  "exclude": [
    "packages/client/**",
+    "packages/host/directory-picker-native/**",
    "scripts/client-bundle-purity.spec.ts"
  ],
  "references": [
@@ -168,7 +169,6 @@
    { "path": "./packages/host/apiproxy" },
    { "path": "./packages/host/directory-picker" },
    { "path": "./packages/host/directory-picker-browse" },
-    { "path": "./packages/host/directory-picker-native" },
    { "path": "./packages/host/webserver" },
    { "path": "./packages/sdk/sdk-client" },
    { "path": "./packages/sdk/helper" },