diff --git a/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.i18n.yaml b/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.i18n.yaml
index 8a56329d79..a259edb5ff 100644
--- a/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.i18n.yaml
+++ b/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md
-2026-07-28-directory-picker-capability-seam.md: 622571efc14f40e266e88229a60befa6bdcd6db9
-2026-07-28-directory-picker-capability-seam.zh.md: fbe42ccd81544e79af4078157345cf330c0b3510
+2026-07-28-directory-picker-capability-seam.md: 7d6a78a735a02ae1d17616c63da1acf9a9117ba9
+2026-07-28-directory-picker-capability-seam.zh.md: 1306eae397e2a4c11603264d434ced3b4113f9b2
diff --git a/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md b/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md
index 622571efc1..7d6a78a735 100644
--- a/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md
+++ b/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md
@@ -20,7 +20,7 @@ Placement and policy rulings folded into this decision:
 - **Dependency survey (hand-roll vs adopt).** Node's stdlib *is* the maintained cross-platform OS layer (`readdir(withFileTypes)`, `homedir`, path semantics); surveyed alternatives fail the dependency bar — file-manager packages (`node-file-manager`, `files-and-folders`, Syncfusion's provider) are whole HTTP apps (fit), drive-letter helpers (`drivelist` native addon, `windows-drive-letters` ~7y stale) fail health/proportionality. The browse backend is a thin adapter over stdlib.
 - **Hidden entries: return-and-flag.** The host stamps `hidden` (POSIX dot convention) and returns everything; the client filters. Display policy stays client-side, and the planned show-hidden toggle becomes a client-only change. Windows' `FILE_ATTRIBUTE_HIDDEN` is not exposed by dirents — documented limitation until a native probe pays for itself.
 - **Symlinks: follow for enterability.** `stat` probes symlinks (broken/cyclic → skipped); crumbs keep the logical path the operator navigated, and `workspace.create` already canonicalizes via realpath at adoption.
-- **Listing levels are bounded.** One `list` call materializes at most `maxEntries` rows (config, default 1000 — GitHub's web-UI directory-listing bound): candidates sort before probing so a cut level keeps the name-sorted head and probing stops with the bound, and the wire `DirectoryListing` carries a required `truncated` flag so the client states incompleteness instead of silently missing tail entries. An unbounded level is a memory/responsiveness hole for large or adversarial directories.
+- **Listing levels are bounded, and streamed.** One `list` call returns at most `maxEntries` rows (config, default 1000 — GitHub's web-UI directory-listing bound). The level streams via `opendir` into a name-sorted window of `maxEntries + 1` candidates, so memory stays O(maxEntries) and enterability probing touches only windowed candidates; the wire `DirectoryListing` carries a required `truncated` flag so the client states incompleteness instead of silently missing tail entries. A windowed broken symlink is not backfilled from beyond the window — the eviction already marks the level truncated. An unbounded level is a memory/responsiveness hole for large or adversarial directories.
 - **Whole-filesystem scope, no roots config.** `workspace.create` accepts arbitrary paths and the API serves bash-driving methods, so a browse root would be UX scoping, not a boundary; configurability without a consumer fails the evidence bar. Deferred until a deployment needs it.
 - **The native backend stays.** Plugin-form was the point: multiple providers can serve the seam (an Electron shell would provide the `native` interaction through its own dialog API). Kind naming: `dialog` was the first pick and was dropped — the browse interaction also presents a dialog (the in-app modal), so the word failed to discriminate; `native` names where the chooser runs.
 
diff --git a/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.zh.md b/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.zh.md
index fbe42ccd81..1306eae397 100644
--- a/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.zh.md
+++ b/.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.zh.md
@@ -20,7 +20,7 @@ web GUI 的"打开本地文件夹"流程被焊死在一种交互上：`host.pick
 - **依赖调研（手写 vs 引入）。** Node 标准库本身就是维护中的跨平台 OS 层（`readdir(withFileTypes)`、`homedir`、路径语义）；调研过的替代品都过不了依赖门槛——文件管理器包（`node-file-manager`、`files-and-folders`、Syncfusion 的 provider）是整套 HTTP 应用（契合度不过），盘符工具（原生插件 `drivelist`、约七年未更的 `windows-drive-letters`）健康度／比例失当。browse 后端是标准库上的薄适配。
 - **隐藏条目：返回并打标。** 宿主标注 `hidden`（POSIX 点前缀约定）并返回全部条目；客户端过滤。展示策略留在客户端，计划中的"显示隐藏"开关变成纯客户端改动。Windows 的 `FILE_ATTRIBUTE_HIDDEN` 不被 dirent 暴露——记为限制，直到原生探测值回其成本。
 - **符号链接：为可进入性而跟随。** 用 `stat` 探测符号链接（断链／循环→跳过）；面包屑保留操作者导航的逻辑路径，`workspace.create` 在接纳时本就做 realpath 规范化。
-- **列举层级有上限。** 单次 `list` 至多物化 `maxEntries` 行（配置项，默认 1000——GitHub 网页端目录列举的同一上限）：候选先按名排序再探测，因此被截断的层级保留排序后的头部、探测随上限一同停止；线上 `DirectoryListing` 携带必填的 `truncated` 标志，让客户端明示不完整而不是静默缺尾。无上限的层级对超大或恶意构造的目录就是内存／响应性漏洞。
+- **列举层级有上限，且流式处理。** 单次 `list` 至多返回 `maxEntries` 行（配置项，默认 1000——GitHub 网页端目录列举的同一上限）。层级经 `opendir` 流入一个按名排序、容量 `maxEntries + 1` 的候选窗口，内存保持 O(maxEntries)，可进入性探测只触及窗口内候选；线上 `DirectoryListing` 携带必填的 `truncated` 标志，让客户端明示不完整而不是静默缺尾。窗口内的断链符号链接不从窗口外回填——发生过驱逐本身已把层级标记为截断。无上限的层级对超大或恶意构造的目录就是内存／响应性漏洞。
 - **全盘可浏览，不做 roots 配置。** `workspace.create` 接受任意路径且 API 本就提供驱动 bash 的方法，浏览根只会是 UX 范围而非边界；没有消费方的可配置性过不了证据门槛。等到有部署需要再做。
 - **native 后端保留。** 插件化正是目的：多方都能提供该 seam（Electron 壳可以经自己的对话框 API 提供 `native` 交互）。kind 命名：最初选了 `dialog` 后被放弃——browse 交互同样以对话框呈现（应用内弹窗），这个词起不到判别作用；`native` 命名的是选择器运行的位置。
 
diff --git a/docs/config-catalog.md b/docs/config-catalog.md
index 865e97a555..8db82e5cc7 100644
--- a/docs/config-catalog.md
+++ b/docs/config-catalog.md
@@ -533,7 +533,7 @@ export interface Config {
 }
 ```
 
-Source: [`packages/host/directory-picker-browse/src/index.ts:85`](../packages/host/directory-picker-browse/src/index.ts)
+Source: [`packages/host/directory-picker-browse/src/index.ts:114`](../packages/host/directory-picker-browse/src/index.ts)
 
 ## `@deepseek-ai/dsh-host-webserver`
 
diff --git a/packages/client/test-runtime/src/workspaces.ts b/packages/client/test-runtime/src/workspaces.ts
index ee635a5fd8..cc9f60bd5c 100644
--- a/packages/client/test-runtime/src/workspaces.ts
+++ b/packages/client/test-runtime/src/workspaces.ts
@@ -119,7 +119,7 @@ export class TestWorkspaces implements IWorkspaces {
     this.calls.push({ method: 'listDirectory', args: [path] })
     const stub = this.stubs.get('listDirectory')
     if (stub !== undefined) return await (stub(path) as Promise<DirectoryListing>)
-    return { path: '/home/test', home: '/home/test', crumbs: [{ name: '/', path: '/', hidden: false }], entries: [] }
+    return { path: '/home/test', home: '/home/test', crumbs: [{ name: '/', path: '/', hidden: false }], entries: [], truncated: false }
   }
 
   /**
diff --git a/packages/client/ui-workspace/src/client/WorkspacePicker.tsx b/packages/client/ui-workspace/src/client/WorkspacePicker.tsx
index fa6290e1f1..903b0e115b 100644
--- a/packages/client/ui-workspace/src/client/WorkspacePicker.tsx
+++ b/packages/client/ui-workspace/src/client/WorkspacePicker.tsx
@@ -98,9 +98,12 @@ export function WorkspaceCreateFlow({
   const flowAvailable = useDirectoryFlow(occupied => occupied)
   // An occupant that unloads mid-interaction leaves nobody to cancel: an
   // open flow over an empty hole withdraws so the menu actions come back.
+  // flowOpen is a dependency because the flow can also OPEN over an already
+  // empty hole (Choose again after the occupant unloaded with the error
+  // dialog up) — that transition must snap back too, not just occupancy loss.
   useEffect(() => {
-    if (!flowAvailable) setFlowOpen(false)
-  }, [flowAvailable])
+    if (flowOpen && !flowAvailable) setFlowOpen(false)
+  }, [flowOpen, flowAvailable])
   const createEntries: MenuEntry[] = [
     ...(flowAvailable
       ? [{ id: OPEN_LOCAL_FOLDER, label: 'Open local folder…', icon: <IconFolderClose16 size={16} />, disabled: flowBusy }]
@@ -224,7 +227,9 @@ export function WorkspaceCreateFlow({
         footer={(
           <>
             <Button variant="outline" className={css.modalAction} onClick={closeModal}>Cancel</Button>
-            <Button variant="primary" className={css.modalAction} onClick={openLocalFolder}>Choose again</Button>
+            {/* Retrying needs an occupant to serve the flow; without one the
+              * button would open a flow nobody can answer or cancel. */}
+            <Button variant="primary" className={css.modalAction} disabled={!flowAvailable} onClick={openLocalFolder}>Choose again</Button>
           </>
         )}
       >
diff --git a/packages/client/ui-workspace/tests/workspace-picker.spec.tsx b/packages/client/ui-workspace/tests/workspace-picker.spec.tsx
index 18ddd8b1fd..490a86d782 100644
--- a/packages/client/ui-workspace/tests/workspace-picker.spec.tsx
+++ b/packages/client/ui-workspace/tests/workspace-picker.spec.tsx
@@ -303,6 +303,20 @@ describe('WorkspacePicker', () => {
     expect(screen.getByRole('menuitem', { name: 'Open local folder…' })).toBeTruthy()
   })
 
+  it('keeps Choose again inert while the flow occupant is gone, and snaps back a flow opened over an empty hole', async () => {
+    const b = mount([], vi.fn(async () => { throw new Error('adoption failed') }))
+    chooseItem('Open local folder…')
+    await act(async () => { b.probe.owner!.onPicked('/one/project') })
+    await waitFor(() => { expect(screen.getByRole('dialog', { name: 'Couldn’t open folder' })).toBeTruthy() })
+    // The occupant unloads while the error dialog is up: retrying would open
+    // a flow nobody can serve or cancel, so the button goes inert.
+    act(() => { b.occupancy.flip(false) })
+    expect(screen.getByRole<HTMLButtonElement>('button', { name: 'Choose again' }).disabled).toBe(true)
+    // Cancel stays the way out, and the menu actions are usable again.
+    fireEvent.click(screen.getByRole('button', { name: 'Cancel' }))
+    expect(screen.getByRole<HTMLButtonElement>('menuitem', { name: 'Create a new workspace' }).disabled).toBe(false)
+  })
+
   it('withdraws an open flow when its occupant unloads, re-enabling the menu actions', () => {
     const b = mount([])
     chooseItem('Open local folder…')
diff --git a/packages/host/directory-picker-browse/README.i18n.yaml b/packages/host/directory-picker-browse/README.i18n.yaml
index 01c7f59933..f6cf3fe8d0 100644
--- a/packages/host/directory-picker-browse/README.i18n.yaml
+++ b/packages/host/directory-picker-browse/README.i18n.yaml
@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/host/directory-picker-browse/README.md
-README.md: 699bc88ea3f2df6b96861d7a02543dcf5c692a63
-README.zh.md: bac45f708a1a7407bd95b5e1aaa947dc1b16bf26
+README.md: 36349a607cdcf99ce2b8c9ee767ffd4d896a64a3
+README.zh.md: 0108e37bd7c4213bf057a42af2026beb6bf53d45
diff --git a/packages/host/directory-picker-browse/README.md b/packages/host/directory-picker-browse/README.md
index 699bc88ea3..36349a607c 100644
--- a/packages/host/directory-picker-browse/README.md
+++ b/packages/host/directory-picker-browse/README.md
@@ -4,7 +4,7 @@ English | [中文](README.zh.md)
 
 The **in-app browsing backend** of the [directory-picker seam](../directory-picker/README.md): `BrowseDirectoryPicker` registers `ctx.directoryPicker` with the `browse` capability — one-level directory listing and child-directory creation over Node's stdlib, which already carries the per-OS adaptation. Nothing renders on the host display, so this backend serves remote clients the native backend cannot.
 
-Behavior facts: listings return **directories only**, name-sorted, with symlinks-to-directories followed (broken/cyclic links skipped — the probe `stat` failing means "not enterable") and a host-owned `hidden` flag (POSIX dot convention) left for the client to act on; `crumbs` is the root-to-target ancestor chain, the root crumb labeled by its full path (`/`, `C:\`); an absent `list` path means the host account's home directory. `createDirectory` is non-recursive (a missing parent is a real failure, not a level to invent) and validates the name as a single non-blank segment even when called directly, mirroring the wire schema's fence. Both primitives reject an explicit path that is not fully qualified — relative forms, and on Windows the rooted drive-less forms (`\foo`, `/foo`) and incomplete UNC prefixes (`\\`, `\\server`) that `isAbsolute` accepts — with `directory-unreadable`/`directory-create-failed`, instead of letting `resolve` rebase it under the host process cwd or current drive. One `list` call materializes at most `maxEntries` rows (config, default 1000 — the bound GitHub's web UI applies to directory listings): a cut level keeps the name-sorted head, counts hidden rows against the bound, stops probing once the bound is hit, and reports `truncated: true` so the client can say the level is incomplete. Failures throw the seam's typed `DirectoryPickerError`. Policy rationale: [the directory-picker capability seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md).
+Behavior facts: listings return **directories only**, name-sorted, with symlinks-to-directories followed (broken/cyclic links skipped — the probe `stat` failing means "not enterable") and a host-owned `hidden` flag (POSIX dot convention) left for the client to act on; `crumbs` is the root-to-target ancestor chain, the root crumb labeled by its full path (`/`, `C:\`); an absent `list` path means the host account's home directory. `createDirectory` is non-recursive (a missing parent is a real failure, not a level to invent) and validates the name as a single non-blank segment even when called directly, mirroring the wire schema's fence. Both primitives reject an explicit path that is not fully qualified — relative forms, and on Windows the rooted drive-less forms (`\foo`, `/foo`) and incomplete UNC prefixes (`\\`, `\\server`) that `isAbsolute` accepts — with `directory-unreadable`/`directory-create-failed`, instead of letting `resolve` rebase it under the host process cwd or current drive. One `list` call returns at most `maxEntries` rows (config, default 1000 — the bound GitHub's web UI applies to directory listings), and the level streams through a bounded window so memory stays O(maxEntries) no matter how many children the directory holds: a cut level keeps the name-sorted head, counts hidden rows against the bound, probes only windowed candidates, and reports `truncated: true` so the client can say the level is incomplete (a windowed broken symlink is not backfilled from beyond the window — the eviction already marks the level truncated). Failures throw the seam's typed `DirectoryPickerError`. Policy rationale: [the directory-picker capability seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md).
 
 **Dual-face package**: the browser half (`./client`) fills [ui-workspace's](../../client/ui-workspace/README.md) two directory-flow holes with the in-app **Select Workspace Directory** dialog (figma `Harness` 813-23126 family — Miller two-column view, breadcrumb with a click-to-edit path zone, nested New-folder dialog), driving `host.listDirectory`/`host.createDirectory` and registering its own locale namespace (`directory-browser`, zh default / en). One cordis.yml row therefore composes both sides of the browse interaction; the client carries no capability-kind branching, and mounting a second flow package fails at load (the holes are `single` kind).
 
diff --git a/packages/host/directory-picker-browse/README.zh.md b/packages/host/directory-picker-browse/README.zh.md
index bac45f708a..0108e37bd7 100644
--- a/packages/host/directory-picker-browse/README.zh.md
+++ b/packages/host/directory-picker-browse/README.zh.md
@@ -4,7 +4,7 @@
 
 [目录选择 seam](../directory-picker/README.md) 的**应用内浏览后端**：`BrowseDirectoryPicker` 以 `browse` 能力注册 `ctx.directoryPicker`——基于 Node 标准库（跨 OS 适配本就由它承担）提供单层目录列举与子目录创建。宿主屏幕上不渲染任何东西，因此该后端能服务 native 后端无法触及的远程客户端。
 
-行为事实：列举**只返回目录**、按名称排序，指向目录的符号链接会被跟随（断链／循环链接被跳过——探测 `stat` 失败即"不可进入"），并携带宿主判定的 `hidden` 标志（POSIX 点前缀约定），展示决策留给客户端；`crumbs` 是从根到目标的祖先链，根 crumb 以完整路径标注（`/`、`C:\`）；`list` 不带路径即列举宿主账户的家目录。`createDirectory` 不递归（父目录缺失是真实失败，不是要补造的层级），且即便被直接调用也把名称校验为单个非空段，与协议 schema 的栅栏一致。两个原语都拒绝非完全限定的显式路径——相对形态，以及 Windows 上 `isAbsolute` 会放行的无盘符有根形态（`\foo`、`/foo`）与不完整的 UNC 前缀（`\\`、`\\server`）——报 `directory-unreadable`／`directory-create-failed`，而不是任由 `resolve` 把它重定位到宿主进程 cwd 或当前盘符之下。单次 `list` 至多物化 `maxEntries` 行（配置项，默认 1000——GitHub 网页端对目录列举采用的同一上限）：被截断的层级保留按名排序的头部、隐藏行计入上限、达到上限即停止探测，并报告 `truncated: true`，供客户端提示层级不完整。失败抛出 seam 的类型化 `DirectoryPickerError`。策略依据：[目录选择能力 seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md)。
+行为事实：列举**只返回目录**、按名称排序，指向目录的符号链接会被跟随（断链／循环链接被跳过——探测 `stat` 失败即"不可进入"），并携带宿主判定的 `hidden` 标志（POSIX 点前缀约定），展示决策留给客户端；`crumbs` 是从根到目标的祖先链，根 crumb 以完整路径标注（`/`、`C:\`）；`list` 不带路径即列举宿主账户的家目录。`createDirectory` 不递归（父目录缺失是真实失败，不是要补造的层级），且即便被直接调用也把名称校验为单个非空段，与协议 schema 的栅栏一致。两个原语都拒绝非完全限定的显式路径——相对形态，以及 Windows 上 `isAbsolute` 会放行的无盘符有根形态（`\foo`、`/foo`）与不完整的 UNC 前缀（`\\`、`\\server`）——报 `directory-unreadable`／`directory-create-failed`，而不是任由 `resolve` 把它重定位到宿主进程 cwd 或当前盘符之下。单次 `list` 至多返回 `maxEntries` 行（配置项，默认 1000——GitHub 网页端对目录列举采用的同一上限），且层级以流式方式经过一个有界窗口，无论目录有多少子项内存都保持 O(maxEntries)：被截断的层级保留按名排序的头部、隐藏行计入上限、只探测窗口内候选，并报告 `truncated: true`，供客户端提示层级不完整（窗口内的断链符号链接不会从窗口外回填——发生过驱逐本身已把层级标记为截断）。失败抛出 seam 的类型化 `DirectoryPickerError`。策略依据：[目录选择能力 seam Agent Note](../../../.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md)。
 
 **双面包**：browser half（`./client`）以应用内 **选择工作区目录** 对话框（figma `Harness` 813-23126 家族——Miller 双列视图、带点击即编辑路径区的面包屑、嵌套新建文件夹对话框）填入 [ui-workspace](../../client/ui-workspace/README.md) 的两个目录流洞，驱动 `host.listDirectory`／`host.createDirectory`，并注册自己的 locale 命名空间（`directory-browser`，zh 默认／en）。因此一行 cordis.yml 同时组合浏览交互的两侧；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）。
 
diff --git a/packages/host/directory-picker-browse/package.json b/packages/host/directory-picker-browse/package.json
index 192ce614d2..a9f3fc2090 100644
--- a/packages/host/directory-picker-browse/package.json
+++ b/packages/host/directory-picker-browse/package.json
@@ -33,7 +33,8 @@
   "license": "BSD-3-Clause",
   "dependencies": {
     "@deepseek-ai/dsh-host-directory-picker": "workspace:^",
-    "clsx": "^2.0.0"
+    "clsx": "^2.0.0",
+    "schemastery": "^3.18.0"
   },
   "peerDependencies": {
     "@deepseek-ai/dsh-client-locale": "^0.0.1",
diff --git a/packages/host/directory-picker-browse/src/client/index.ts b/packages/host/directory-picker-browse/src/client/index.ts
index bc409483ab..6eb43829db 100644
--- a/packages/host/directory-picker-browse/src/client/index.ts
+++ b/packages/host/directory-picker-browse/src/client/index.ts
@@ -28,8 +28,12 @@ export const inject = ['slots', 'workspaces', 'locale']
  */
 export function apply(ctx: ClientContext): void {
   ctx.effect(() => {
-    const disposers = [
-      ctx.locale.register(LOCALE_NS, 'zh', {
+    // The two dictionaries land as a unit: if the second registration hits a
+    // rival owner of the namespace, the first rolls back before the throw —
+    // a failed activation must not squat the namespace's other locale.
+    const disposers: (() => void)[] = []
+    const dictionaries: [locale: string, dict: Record<string, string>][] = [
+      ['zh', {
         'browser.title': '选择工作区目录',
         'browser.home': '主目录',
         'browser.newFolder': '新建文件夹',
@@ -42,8 +46,8 @@ export function apply(ctx: ClientContext): void {
         'browser.editPath': '编辑路径',
         'browser.loading': '加载中…',
         'browser.truncated': '文件夹过多，仅显示开头部分。',
-      }),
-      ctx.locale.register(LOCALE_NS, 'en', {
+      }],
+      ['en', {
         'browser.title': 'Select Workspace Directory',
         'browser.home': 'Home',
         'browser.newFolder': 'New folder',
@@ -56,8 +60,14 @@ export function apply(ctx: ClientContext): void {
         'browser.editPath': 'Edit path',
         'browser.loading': 'Loading…',
         'browser.truncated': 'Too many folders to list; only the beginning is shown.',
-      }),
+      }],
     ]
+    try {
+      for (const [locale, dict] of dictionaries) disposers.push(ctx.locale.register(LOCALE_NS, locale, dict))
+    } catch (error) {
+      for (const dispose of disposers.reverse()) dispose()
+      throw error
+    }
     return () => { for (const dispose of disposers) dispose() }
   }, 'directory-picker-browse: dialog dictionaries')
 
diff --git a/packages/host/directory-picker-browse/src/index.ts b/packages/host/directory-picker-browse/src/index.ts
index b9699cd612..20ebef1c62 100644
--- a/packages/host/directory-picker-browse/src/index.ts
+++ b/packages/host/directory-picker-browse/src/index.ts
@@ -9,7 +9,7 @@
  * @module @deepseek-ai/dsh-host-directory-picker-browse
  */
 
-import { mkdir, readdir, stat } from 'node:fs/promises'
+import { mkdir, opendir, stat } from 'node:fs/promises'
 import { homedir } from 'node:os'
 import { basename, dirname, join, posix, resolve, win32 } from 'node:path'
 import type { Context } from 'cordis'
@@ -53,6 +53,35 @@ export function fullyQualified(path: string, platform: NodeJS.Platform = process
     : posix.isAbsolute(path)
 }
 
+/** One streamed listing candidate: the dirent facts a row needs, nothing else retained. */
+export interface ListingCandidate {
+  /** Base name within the streamed level. */
+  name: string
+  /** Dirent says directory (no probe needed). */
+  isDirectory: boolean
+  /** Dirent says symlink (enterability needs a stat probe). */
+  isSymbolicLink: boolean
+}
+
+/**
+ * Insert a streamed candidate into the name-sorted bounded window, evicting
+ * the name-largest candidate when the window exceeds `keep`. Memory over an
+ * arbitrarily large level therefore stays O(keep) regardless of how many
+ * children the directory holds.
+ * @param window - the name-ascending window, mutated in place.
+ * @param candidate - the streamed candidate to place.
+ * @param keep - the window bound.
+ * @returns true when an eviction happened (the level has candidates beyond the window).
+ */
+export function boundedInsert(window: ListingCandidate[], candidate: ListingCandidate, keep: number): boolean {
+  const at = window.findIndex(existing => candidate.name.localeCompare(existing.name) < 0)
+  if (at === -1) window.push(candidate)
+  else window.splice(at, 0, candidate)
+  if (window.length <= keep) return false
+  window.pop()
+  return true
+}
+
 /** Message text of an unknown thrown value. */
 function messageOf(error: unknown): string {
   /* v8 ignore next -- node:fs rejects with Error instances; the String arm only satisfies the unknown narrowing. */
@@ -127,25 +156,32 @@ export default class BrowseDirectoryPicker extends DirectoryPicker {
       throw new DirectoryPickerError('directory-unreadable', path, `cannot list "${path}": not a fully qualified path`)
     }
     const target = resolve(path ?? home)
-    let names: { name: string; isDirectory: boolean; isSymbolicLink: boolean }[]
+    // Stream the level (opendir, one dirent at a time) into a name-sorted
+    // window of maxEntries + 1 candidates: memory stays bounded no matter how
+    // many children the directory holds, the window keeps the name-sorted
+    // head, and the +1 slot lets an in-window extra row prove the cut. A
+    // window candidate that turns out non-enterable (broken symlink) is not
+    // backfilled from beyond the window — an eviction already marks the
+    // level truncated, which stays the honest answer.
+    const keep = this.config.maxEntries + 1
+    const window: ListingCandidate[] = []
+    let evicted = false
     try {
-      const dirents = await readdir(target, { withFileTypes: true })
-      names = dirents.map(dirent => ({
-        name: dirent.name,
-        isDirectory: dirent.isDirectory(),
-        isSymbolicLink: dirent.isSymbolicLink(),
-      }))
+      const level = await opendir(target)
+      for await (const dirent of level) {
+        // Only rows a browser could enter contend for the window; dirent
+        // says "directory" outright, a symlink needs the later stat probe.
+        if (!dirent.isDirectory() && !dirent.isSymbolicLink()) continue
+        const candidate = { name: dirent.name, isDirectory: dirent.isDirectory(), isSymbolicLink: dirent.isSymbolicLink() }
+        if (boundedInsert(window, candidate, keep)) evicted = true
+      }
     } catch (error: unknown) {
       throw new DirectoryPickerError('directory-unreadable', target, `cannot list ${target}: ${messageOf(error)}`)
     }
-    // Sort candidates before probing so the bound keeps the name-sorted head
-    // of the level and probing (symlink stat) stops with the bound instead of
-    // touching every child of an oversized directory.
-    names.sort((a, b) => a.name.localeCompare(b.name))
     const entries: DirectoryEntry[] = []
-    let truncated = false
-    for (const entry of names) {
-      const row = await directoryRow(target, entry.name, entry.isDirectory, entry.isSymbolicLink)
+    let truncated = evicted
+    for (const candidate of window) {
+      const row = await directoryRow(target, candidate.name, candidate.isDirectory, candidate.isSymbolicLink)
       if (row === null) continue
       if (entries.length === this.config.maxEntries) {
         truncated = true
diff --git a/packages/host/directory-picker-browse/tests/client-flow.spec.tsx b/packages/host/directory-picker-browse/tests/client-flow.spec.tsx
index 80e8b19db0..8a9b27b5d7 100644
--- a/packages/host/directory-picker-browse/tests/client-flow.spec.tsx
+++ b/packages/host/directory-picker-browse/tests/client-flow.spec.tsx
@@ -130,6 +130,29 @@ describe('directory-picker-browse client half', () => {
     }
   })
 
+  it('rolls back the zh dictionary when a rival already owns the namespace en slot', async () => {
+    const b = await bench()
+    b.declare()
+    const locale = b.ctx.get('locale') as LocaleService
+    const disposeRival = locale.register('directory-browser', 'en', { 'browser.title': 'rival' })
+    const rejections: unknown[] = []
+    const onUnhandled = (reason: unknown): void => { rejections.push(reason) }
+    // cordis re-raises the apply throw as a late rejection (installFailLoud's contract).
+    process.on('unhandledRejection', onUnhandled)
+    try {
+      const fiber = b.ctx.plugin({ inject: [...inject], apply })
+      await expect(fiber.await()).rejects.toThrow(/already has locale/)
+      // The zh registration rolled back with the failure: once the rival
+      // leaves, a fresh registrant owns the whole namespace again.
+      disposeRival()
+      const disposeZh = locale.register('directory-browser', 'zh', { 'browser.title': '空闲' })
+      disposeZh()
+    } finally {
+      await new Promise(resolve => setTimeout(resolve, 0))
+      process.off('unhandledRejection', onUnhandled)
+    }
+  })
+
   it('registers the dialog dictionaries and binds this package namespace', async () => {
     const b = await bench()
     b.declare()
diff --git a/packages/host/directory-picker-browse/tests/service.spec.ts b/packages/host/directory-picker-browse/tests/service.spec.ts
index 8e7a2ba049..2b01d0d29e 100644
--- a/packages/host/directory-picker-browse/tests/service.spec.ts
+++ b/packages/host/directory-picker-browse/tests/service.spec.ts
@@ -7,7 +7,8 @@ import { afterAll, beforeAll, describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
 import { DirectoryPickerError } from '@deepseek-ai/dsh-host-directory-picker'
 import type { DirectoryPickerBrowseCapability } from '@deepseek-ai/dsh-host-directory-picker'
-import BrowseDirectoryPicker, { fullyQualified } from '../src/index.ts'
+import BrowseDirectoryPicker, { boundedInsert, fullyQualified } from '../src/index.ts'
+import type { ListingCandidate } from '../src/index.ts'
 
 let root: string
 let capability: DirectoryPickerBrowseCapability
@@ -21,6 +22,13 @@ beforeAll(async () => {
   await writeFile(join(root, 'notes.txt'), 'not a directory')
   await symlink(join(root, 'projects'), join(root, 'linked'), 'junction')
   await symlink(join(root, 'gone'), join(root, 'broken'), 'junction')
+  try {
+    await symlink(join(root, 'notes.txt'), join(root, 'file-link'))
+  } catch {
+    // Windows denies unprivileged file symlinks; the file-link row only
+    // feeds the POSIX lanes' coverage of the symlink-to-file arm, and every
+    // assertion below expects it to be filtered out anyway.
+  }
 
   const ctx = new Context()
   const fiber = ctx.plugin(BrowseDirectoryPicker)
@@ -63,11 +71,31 @@ describe('BrowseDirectoryPicker', () => {
       const exact = await bounded.list(join(root, 'projects'))
       expect(exact.entries.map(entry => entry.name)).toEqual(['harness'])
       expect(exact.truncated).toBe(false)
+      // A level that fits the window but exceeds the bound (two rows, bound
+      // one): the in-window extra row proves the cut without any eviction.
+      await mkdir(join(root, 'projects', 'harness', 'a'))
+      await mkdir(join(root, 'projects', 'harness', 'b'))
+      const inWindow = await bounded.list(join(root, 'projects', 'harness'))
+      expect(inWindow.entries.map(entry => entry.name)).toEqual(['a'])
+      expect(inWindow.truncated).toBe(true)
     } finally {
       await fiber.dispose()
     }
   })
 
+  it('boundedInsert keeps the window name-sorted and bounded, reporting evictions', () => {
+    const candidate = (name: string): ListingCandidate => ({ name, isDirectory: true, isSymbolicLink: false })
+    const window: ListingCandidate[] = []
+    expect(boundedInsert(window, candidate('m'), 2)).toBe(false)
+    expect(boundedInsert(window, candidate('z'), 2)).toBe(false)
+    // A smaller name lands in place and pushes the current largest out.
+    expect(boundedInsert(window, candidate('a'), 2)).toBe(true)
+    expect(window.map(entry => entry.name)).toEqual(['a', 'm'])
+    // A name beyond the window's tail enters last and leaves immediately.
+    expect(boundedInsert(window, candidate('t'), 2)).toBe(true)
+    expect(window.map(entry => entry.name)).toEqual(['a', 'm'])
+  })
+
   it('reports the ancestry as jump-target crumbs ending at the listed directory', async () => {
     const listing = await capability.list(join(root, 'projects'))
     const tail = listing.crumbs.at(-1)!
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 36a410c025..f7026700fa 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2798,6 +2798,9 @@ importers:
       clsx:
         specifier: ^2.0.0
         version: 2.1.1
+      schemastery:
+        specifier: ^3.18.0
+        version: 3.18.0
     devDependencies:
       '@deepseek-ai/dsh-client-locale':
         specifier: workspace:^