diff --git a/apps/web/tests/settings-chrome.e2e.ts b/apps/web/tests/settings-chrome.e2e.ts
index f3cf4b3bbe..216dae4dbb 100644
--- a/apps/web/tests/settings-chrome.e2e.ts
+++ b/apps/web/tests/settings-chrome.e2e.ts
@@ -24,6 +24,8 @@ import { ZH_BROWSER_LOCALE, saveFailureShot } from './support.ts'
 const SNAPSHOT_DIR = fileURLToPath(new URL('./snapshots/settings-chrome', import.meta.url))
 const DIALOG_EXPECTED = join(SNAPSHOT_DIR, 'dialog.expected.md')
 const PLUGINS_EXPECTED = join(SNAPSHOT_DIR, 'plugins.expected.md')
+// The English fallback surface: a browser naming no shipped language.
+const DIALOG_EN_EXPECTED = join(SNAPSHOT_DIR, 'dialog-en.expected.md')
 const PLUGIN_ROW_SELECTOR = '[data-plugin-entry$="ui-settings"]'
 const MODE = webSnapshotMode()
 
@@ -496,6 +498,11 @@ describe('web e2e: settings modal and General preferences', () => {
       const dialog = frPage.getByRole('dialog', { name: 'Settings' })
       await dialog.waitFor({ timeout: 10_000 })
       await dialog.getByRole('button', { name: 'English' }).waitFor({ timeout: 10_000 })
+      // Golden of the English fallback dialog — the visible output this change
+      // produces. The zh golden above covers the detected-locale surface, so
+      // the pair pins both directions of the resolution.
+      const snapshot = await captureStableAria(frPage, '[role="dialog"]', fresh.workspaceCwd)
+      await compareOrRefreshGolden(DIALOG_EN_EXPECTED, snapshot, MODE)
       expect(frTripwire.pageErrors).toEqual([])
       expect(frTripwire.warnings).toEqual([])
     } finally {
@@ -506,6 +513,6 @@ describe('web e2e: settings modal and General preferences', () => {
 
   it.skipIf(MODE === 'record')('keeps the fixture inventory closed', async () => {
     expect(tripwire.warnings).toEqual([])
-    await assertFixtureInventory(SNAPSHOT_DIR, ['dialog.expected.md', 'plugins.expected.md'])
+    await assertFixtureInventory(SNAPSHOT_DIR, ['dialog-en.expected.md', 'dialog.expected.md', 'plugins.expected.md'])
   })
 })
diff --git a/apps/web/tests/snapshots/settings-chrome/dialog-en.expected.md b/apps/web/tests/snapshots/settings-chrome/dialog-en.expected.md
new file mode 100644
index 0000000000..605e2fe328
--- /dev/null
+++ b/apps/web/tests/snapshots/settings-chrome/dialog-en.expected.md
@@ -0,0 +1,45 @@
+- dialog "Settings":
+  - navigation:
+    - text: Settings
+    - button "General":
+      - img
+      - text: General
+    - button "Models":
+      - img
+      - text: Models
+    - button "Plugins":
+      - img
+      - text: Plugins
+    - button "Agent presets":
+      - img
+      - text: Agent presets
+  - button "Open configuration file"
+  - button "Close":
+    - img
+    - text: Close
+  - text: Agent preset Applies to sessions you start from now on. Running sessions keep the preset they began with.
+  - button "Standard mode":
+    - text: Standard mode
+    - img
+  - text: Permission Choose the default permission mode for new sessions
+  - button "Workspace Write":
+    - text: Workspace Write
+    - img
+  - text: Language
+  - button "English":
+    - text: English
+    - img
+  - text: Appearance
+  - button "Light":
+    - img
+    - text: Light
+  - button "Dark":
+    - img
+    - text: Dark
+  - button "System" [pressed]:
+    - img
+    - text: System
+  - text: Enter behavior while busy Busy only; Cmd/Ctrl+Enter uses the other behavior
+  - button "Queue":
+    - text: Queue
+    - img
diff --git a/packages/client/locale/README.i18n.yaml b/packages/client/locale/README.i18n.yaml
index 126c4ee685..e1cc2a1c88 100644
--- a/packages/client/locale/README.i18n.yaml
+++ b/packages/client/locale/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/client/locale/README.md
-README.md: a63807f093dc12831a41196e61008151868e3205
-README.zh.md: b302e6055ba30d2db0948c0a6f1551c4a9dcb24c
+README.md: 3fb5cce334e59b36c30f22a863f8e91d260f2ac9
+README.zh.md: 4f08344d6f030e408e570ff0ad31d0b0d4de3ecc
diff --git a/packages/client/locale/README.md b/packages/client/locale/README.md
index a63807f093..3fb5cce334 100644
--- a/packages/client/locale/README.md
+++ b/packages/client/locale/README.md
@@ -2,7 +2,7 @@
 
 English | [中文](README.zh.md)
 
-Locale plugin: LocaleRuntime — the `zh`/`en` preference stored as `locale.preference` in `$DSH_HOME/settings.yaml`; when that explicit Host value is absent, a fresh browser starts provisionally in the language `navigator` asks for (primary-subtag matching, with `zh` when it asks for no language this app ships). The Host read runs after plugin activation so an unavailable settings service cannot block the page; its result replaces the provisional browser value live. Remote browsers retain only a process-local selection because the settings API is loopback-only. `locale/change` fires on switches. The service also owns the ns×locale dictionary registry (typed `register(ns, {zh, en})` checked against `LocaleNamespaceMap`, `bind(ns)`→`TranslateNS<ns>`; lookup chain ns → common → zh → key), implements the slot system's `LocaleFace`, and installs itself through `ctx.slots.installLocale`, backing the framework-injected `t` standard seat (`Translate`/`TranslateNS` are ui-slots types; import them from there — this package only re-exports for dictionary owners' convenience). The [Host-backed preferences decision](../../../.agents/notes/implemented/bug-fix/2026-08-06-host-backed-web-preferences.md) owns the persistence boundary.
+Locale plugin: LocaleRuntime — the `zh`/`en` preference stored as `locale.preference` in `$DSH_HOME/settings.yaml`; when that explicit Host value is absent, a fresh browser starts provisionally in the language `navigator` asks for (primary-subtag matching, with `en` when it asks for no language this app ships). The Host read runs after plugin activation so an unavailable settings service cannot block the page; its result replaces the provisional browser value live. Remote browsers retain only a process-local selection because the settings API is loopback-only. `locale/change` fires on switches, and the plugin points `<html lang>` at the active locale (`zh-CN`/`en`) on activation and on every switch. The service also owns the ns×locale dictionary registry (typed `register(ns, {zh, en})` checked against `LocaleNamespaceMap`, `bind(ns)`→`TranslateNS<ns>`; lookup chain ns → common → en → key), implements the slot system's `LocaleFace`, and installs itself through `ctx.slots.installLocale`, backing the framework-injected `t` standard seat (`Translate`/`TranslateNS` are ui-slots types; import them from there — this package only re-exports for dictionary owners' convenience). The [Host-backed preferences decision](../../../.agents/notes/implemented/bug-fix/2026-08-06-host-backed-web-preferences.md) owns the persistence boundary.
 
 ## Model Experience
 
diff --git a/packages/client/locale/README.zh.md b/packages/client/locale/README.zh.md
index b302e6055b..4f08344d6f 100644
--- a/packages/client/locale/README.zh.md
+++ b/packages/client/locale/README.zh.md
@@ -2,7 +2,7 @@
 
 [English](README.md) | 中文
 
-locale 插件：LocaleRuntime——`zh`／`en` 偏好以 `locale.preference` 存储在 `$DSH_HOME/settings.yaml` 中；若没有显式 Host 值，全新浏览器会暂时使用 `navigator` 请求的语言（按主子标签匹配；若其请求的语言本应用都不提供，则使用 `zh`）。Host 读取在插件激活后执行，因此 settings 服务不可用不会阻塞页面；读取结果会实时替换浏览器暂定值。settings API 仅限回环请求，因此远程浏览器的选择仅保留在进程内。`locale/change` 仅在切换语言时触发。该服务还拥有 ns×locale 字典注册表（类型化 `register(ns, {zh, en})` 按 `LocaleNamespaceMap` 校验，`bind(ns)`→`TranslateNS<ns>`；查找链 ns → common → zh → key），实现 slot 系统的 `LocaleFace`，并经 `ctx.slots.installLocale` 自行安装，支撑框架注入的 `t` 标准席位（`Translate`／`TranslateNS` 是 ui-slots 的类型；请从那里导入——本包的再导出仅为字典所有者提供便利）。该持久化边界由[Host settings 支撑的偏好决策](../../../.agents/notes/implemented/bug-fix/2026-08-06-host-backed-web-preferences.md)拥有。
+locale 插件：LocaleRuntime——`zh`／`en` 偏好以 `locale.preference` 存储在 `$DSH_HOME/settings.yaml` 中；若没有显式 Host 值，全新浏览器会暂时使用 `navigator` 请求的语言（按主子标签匹配；若其请求的语言本应用都不提供，则使用 `en`）。Host 读取在插件激活后执行，因此 settings 服务不可用不会阻塞页面；读取结果会实时替换浏览器暂定值。settings API 仅限回环请求，因此远程浏览器的选择仅保留在进程内。`locale/change` 仅在切换语言时触发；插件会在激活时以及每次切换时把 `<html lang>` 指向当前 locale（`zh-CN`／`en`）。该服务还拥有 ns×locale 字典注册表（类型化 `register(ns, {zh, en})` 按 `LocaleNamespaceMap` 校验，`bind(ns)`→`TranslateNS<ns>`；查找链 ns → common → en → key），实现 slot 系统的 `LocaleFace`，并经 `ctx.slots.installLocale` 自行安装，支撑框架注入的 `t` 标准席位（`Translate`／`TranslateNS` 是 ui-slots 的类型；请从那里导入——本包的再导出仅为字典所有者提供便利）。该持久化边界由[Host settings 支撑的偏好决策](../../../.agents/notes/implemented/bug-fix/2026-08-06-host-backed-web-preferences.md)拥有。
 
 ## 模型体验
 
diff --git a/packages/client/locale/src/client/index.ts b/packages/client/locale/src/client/index.ts
index ab84f054ad..3f14acf216 100644
--- a/packages/client/locale/src/client/index.ts
+++ b/packages/client/locale/src/client/index.ts
@@ -197,13 +197,20 @@ export class LocaleRuntime {
 
   /**
    * Switch the active locale — the only user preference write entry.
+   *
+   * The durable write happens even when the id already matches the active
+   * locale, because the active value may be a provisional browser-derived or
+   * fallback resolution that nothing has stored yet. Picking the language
+   * already on screen is still an explicit choice, and it must survive a
+   * different browser sharing the same DSH home. Only the render notification
+   * is conditional: republishing an unchanged locale would churn every
+   * subscriber for nothing.
    * @param id - a registered locale id; unknown ids throw.
    */
   setLocale(id: string): void {
     const match = this.snapshot.locales.find(l => l.id === id)
     if (match === undefined) throw new Error(`locale "${id}" is not registered`)
-    if (this.snapshot.active === match.id) return
-    this.publish(match.id, true)
+    if (this.snapshot.active !== match.id) this.publish(match.id, true)
     void this.host?.set(LOCALE_PREFERENCE_FIELD, match.id)
   }
 
diff --git a/packages/client/locale/tests/apply.client.spec.ts b/packages/client/locale/tests/apply.client.spec.ts
index a5c70ed624..4f4d08a951 100644
--- a/packages/client/locale/tests/apply.client.spec.ts
+++ b/packages/client/locale/tests/apply.client.spec.ts
@@ -2,7 +2,7 @@
  * Language row registration, snapshot projection into the row store, and
  * recovery after an HMR collapse of the declaring entry. */
 import { Context } from '@deepseek-ai/cordis'
-import { afterEach, describe, expect, it, vi } from 'vitest'
+import { describe, expect, it, vi } from 'vitest'
 import { SlotRegistry } from '@deepseek-ai/dsh-client-runtime/client'
 import { SettingsSchemaService } from '@deepseek-ai/dsh-client-ui-settings/src/client/schema.ts'
 import { SettingsScopeBinder } from '@deepseek-ai/dsh-client-ui-settings/src/client/settings-scope.ts'
@@ -78,10 +78,6 @@ describe('locale apply', () => {
   // localized copy sets its locale explicitly via setLocale/Host preference
   // rather than leaning on FALLBACK_LOCALE. This file has no jsdom environment,
   // so there is no `window` and no browser-language detection to stub.
-  afterEach(() => {
-    vi.unstubAllGlobals()
-  })
-
   it('declares the slot service', () => {
     expect(inject).toEqual(['slots', 'connection', 'remote', 'settingsScope'])
   })
diff --git a/packages/client/locale/tests/locale.client.spec.ts b/packages/client/locale/tests/locale.client.spec.ts
index eb279f1295..a945ccd07e 100644
--- a/packages/client/locale/tests/locale.client.spec.ts
+++ b/packages/client/locale/tests/locale.client.spec.ts
@@ -138,7 +138,7 @@ describe('LocaleRuntime', () => {
     expect(svc.getSnapshot().revision).toBe(before + 1)
   })
 
-  it('setLocale writes through the scope, republishes an immutable snapshot, and no-ops on same value', () => {
+  it('setLocale writes through the scope and republishes only on a real change', () => {
     const host = stubSettingsScope<LocaleSettings>()
     const { svc, events } = make(host)
     svc.setLocale('en')
@@ -147,9 +147,27 @@ describe('LocaleRuntime', () => {
     expect(events).toHaveLength(1)
     expect(events[0]).toBe(svc.getLocale())
     expect(events[0]!.revision).toBe(1)
+    // Re-selecting the active locale publishes nothing (no subscriber churn)
+    // but still writes: the active value may be a provisional browser-derived
+    // resolution nothing has stored, and picking it is an explicit choice that
+    // must outlive this browser.
     svc.setLocale('en')
     expect(events).toHaveLength(1)
-    expect(host.set).toHaveBeenCalledOnce()
+    expect(host.set).toHaveBeenCalledTimes(2)
+    expect(host.set).toHaveBeenLastCalledWith('preference', 'en')
+  })
+
+  it('persists an explicit pick of the provisional locale, so a shared DSH home agrees', () => {
+    // A browser naming no shipped language opens at FALLBACK_LOCALE with
+    // nothing stored. Choosing that same language in the menu must become
+    // durable, or a Chinese browser sharing the home still opens Chinese.
+    stubLanguages('fr-FR')
+    const host = stubSettingsScope<LocaleSettings>()
+    const { svc } = make(host)
+    expect(svc.getLocale().active).toBe('en')
+    expect(host.set).not.toHaveBeenCalled()
+    svc.setLocale('en')
+    expect(host.set).toHaveBeenCalledWith('preference', 'en')
   })
 
   it('setLocale without a host scope stays process-local', () => {
diff --git a/packages/client/ui-agent-preset/tests/apply.client.spec.ts b/packages/client/ui-agent-preset/tests/apply.client.spec.ts
index 7d998c7e11..e0d5c69e4e 100644
--- a/packages/client/ui-agent-preset/tests/apply.client.spec.ts
+++ b/packages/client/ui-agent-preset/tests/apply.client.spec.ts
@@ -21,7 +21,6 @@ import type { AgentPresetSectionInjected } from '../src/client/AgentPresetSectio
 import { AgentPresetSeat } from '../src/client/AgentPresetSeat.tsx'
 import type { AgentPresetSeatInjected } from '../src/client/AgentPresetSeat.tsx'
 
-
 const ROSTER_ONE = {
   rpcId: 'r',
   result: {
diff --git a/packages/client/ui-input-trigger/tests/apply.client.spec.ts b/packages/client/ui-input-trigger/tests/apply.client.spec.ts
index f5d04fcfd6..e66fb73262 100644
--- a/packages/client/ui-input-trigger/tests/apply.client.spec.ts
+++ b/packages/client/ui-input-trigger/tests/apply.client.spec.ts
@@ -12,7 +12,6 @@ import type { SessionId } from '@deepseek-ai/dsh-client-runtime/client'
 import { apply, inject, InputTriggerService } from '@deepseek-ai/dsh-client-ui-input-trigger/client'
 import type { MenuViewInjected } from '@deepseek-ai/dsh-client-ui-input-trigger/client'
 
-
 const sid = (k: string): SessionId => k as SessionId
 
 async function bench() {
diff --git a/packages/client/ui-settings-general/tests/apply.client.spec.ts b/packages/client/ui-settings-general/tests/apply.client.spec.ts
index 79d597f9bc..f8c7407e5a 100644
--- a/packages/client/ui-settings-general/tests/apply.client.spec.ts
+++ b/packages/client/ui-settings-general/tests/apply.client.spec.ts
@@ -10,7 +10,6 @@ import { GeneralSection } from '../src/client/GeneralSection.tsx'
 import { SettingsDocumentAction } from '../src/client/SettingsDocumentAction.tsx'
 import type { SettingsDocumentActionInjected } from '../src/client/SettingsDocumentAction.tsx'
 
-
 /** The seats this plugin fills for a loopback browser (slot name → expected component). */
 const SEATS = [
   ['settings.trigger', TriggerContent],
diff --git a/packages/client/ui-settings-models/tests/apply.client.spec.ts b/packages/client/ui-settings-models/tests/apply.client.spec.ts
index d73950a6f7..385f726d36 100644
--- a/packages/client/ui-settings-models/tests/apply.client.spec.ts
+++ b/packages/client/ui-settings-models/tests/apply.client.spec.ts
@@ -11,7 +11,6 @@ import { ModelsSection } from '../src/client/ModelsSection.tsx'
 import { DeepSeekOnboardingDialog } from '../src/client/DeepSeekOnboardingDialog.tsx'
 import { WelcomeNotice } from '../src/client/WelcomeNotice.tsx'
 
-
 async function bench(isLoopback = true) {
   const ctx = new Context()
   await ctx.plugin(SlotRegistry).await()
diff --git a/packages/client/ui-settings-plugins/tests/apply.client.spec.ts b/packages/client/ui-settings-plugins/tests/apply.client.spec.ts
index d8022887fa..c3987e38a5 100644
--- a/packages/client/ui-settings-plugins/tests/apply.client.spec.ts
+++ b/packages/client/ui-settings-plugins/tests/apply.client.spec.ts
@@ -13,7 +13,6 @@ import type {
   ConfigurablePluginsTabFace, PluginsSettingsSectionInjected,
 } from '@deepseek-ai/dsh-client-ui-settings-plugins/client'
 
-
 /**
  * @param served - namespaces the Host describes; omitted answers a failed read,
  * which is what most of these specs want (no card has anything to render).
@@ -87,7 +86,6 @@ describe('ui-settings-plugins apply', () => {
     expect(slots.spec('settings.plugin.item')).toMatchObject({ kind: 'keyed', scope: 'root' })
   })
 
-
   it('injects a live tab projection, the card directory, and one business face per card', async () => {
     const { ctx, slots } = await bench()
     declareRoot(slots)
diff --git a/packages/client/ui-theme/tests/apply.client.spec.ts b/packages/client/ui-theme/tests/apply.client.spec.ts
index 0ac3dc32b8..fa20e0dd3b 100644
--- a/packages/client/ui-theme/tests/apply.client.spec.ts
+++ b/packages/client/ui-theme/tests/apply.client.spec.ts
@@ -14,7 +14,6 @@ import { THEME_SETTINGS_NAMESPACE, ThemeSettingsSchema } from '../src/theme-sett
 import { AppearanceRow } from '../src/client/AppearanceRow.tsx'
 import type { createAppearanceRowStore } from '../src/client/settings-store.ts'
 
-
 const SLOT = 'settings.general.item'
 
 function deferred<T>() {
diff --git a/packages/client/ui-workspace/tests/apply.client.spec.ts b/packages/client/ui-workspace/tests/apply.client.spec.ts
index 4a819c8587..abba4371c2 100644
--- a/packages/client/ui-workspace/tests/apply.client.spec.ts
+++ b/packages/client/ui-workspace/tests/apply.client.spec.ts
@@ -7,7 +7,6 @@ import type { WorkspaceBrowserInjected, WorkspacePickerInjected } from '@deepsee
 import { WorkspaceBrowser } from '../src/client/WorkspaceBrowser.tsx'
 import { WorkspacePicker } from '../src/client/WorkspacePicker.tsx'
 
-
 async function bench() {
   const ctx = new Context()
   await ctx.plugin(SlotRegistry).await()
diff --git a/packages/extensions/cordis-client-runner/src/client/api-catalog.ts b/packages/extensions/cordis-client-runner/src/client/api-catalog.ts
index 58bbbdee3f..c6539aa46a 100644
--- a/packages/extensions/cordis-client-runner/src/client/api-catalog.ts
+++ b/packages/extensions/cordis-client-runner/src/client/api-catalog.ts
@@ -106,7 +106,7 @@ export const SERVICE_API: readonly ServiceApiEntry[] = [
   {
     key: 'locale',
     summary: 'Dictionary registry plus locale preference.',
-    description: 'Dictionary registry plus locale preference. Lookup chain per key: the entry\'s namespace in the active locale -> that namespace\'s zh fallback -> the shared common namespace (active, then zh) -> the key itself (missing text stays visible, fail loud in the UI rather than blank). Reads go through getLocale; writes only through setLocale; continuous sync through the `locale/change` event, or through the LocaleFace getSnapshot/subscribe pair the render machinery consumes (installed via `ctx.slots.installLocale`).',
+    description: 'Dictionary registry plus locale preference. Lookup chain per key: the entry\'s namespace in the active locale -> that namespace\'s en fallback -> the shared common namespace (active, then en) -> the key itself (missing text stays visible, fail loud in the UI rather than blank). Reads go through getLocale; writes only through setLocale; continuous sync through the `locale/change` event, or through the LocaleFace getSnapshot/subscribe pair the render machinery consumes (installed via `ctx.slots.installLocale`).',
     methods: [
       {
         signature: 'getLocale(): LocaleSnapshot',
diff --git a/scripts/locale-dictionary-parity.spec.ts b/scripts/locale-dictionary-parity.spec.ts
index d48fc3e808..ea40919fd9 100644
--- a/scripts/locale-dictionary-parity.spec.ts
+++ b/scripts/locale-dictionary-parity.spec.ts
@@ -9,83 +9,144 @@
  * only one side breaks that: a reader of the other language sees a bare key
  * such as `list.aria` instead of text. This gate fails on the asymmetry rather
  * than waiting for the bare key to reach a UI.
+ *
+ * Discovery is deliberately broad, because a gate that silently narrows is
+ * worse than no gate. It sweeps every workspace package (not just
+ * `packages/client`), reads dictionaries wherever they are declared —
+ * `locales.ts`, a `locales/` directory, or inline in the plugin body — and
+ * pairs `zh`/`en` across sibling files as well as within one module. A `zh`
+ * dictionary whose `en` counterpart cannot be found anywhere is an error, not
+ * a skip.
  */
 
 import type { Dirent } from 'node:fs'
-import { readdirSync, readFileSync } from 'node:fs'
-import { resolve } from 'node:path'
+import { existsSync, readdirSync, readFileSync } from 'node:fs'
+import { dirname, resolve } from 'node:path'
 import { fileURLToPath } from 'node:url'
 import ts from 'typescript'
 import { describe, expect, it } from 'vitest'
 
 const root = fileURLToPath(new URL('..', import.meta.url))
 
-/** Every `locales*.ts` module under a client package's `src/`. */
-function dictionaryModules(): string[] {
+/** Repo-relative path with `/` separators, so messages and suffix tests match on every OS. */
+function relative(file: string): string {
+  return file.slice(root.length).replaceAll('\\', '/')
+}
+
+/** Every `.ts` source file under each workspace package's `src`, excluding declarations. */
+function sourceFiles(): string[] {
   const files: string[] = []
-  for (const group of ['client', 'extensions']) {
-    const groupRoot = resolve(root, 'packages', group)
-    let packages: string[]
-    try {
-      packages = readdirSync(groupRoot, { withFileTypes: true })
-        .filter(entry => entry.isDirectory())
-        .map(entry => entry.name)
-    } catch {
-      continue
-    }
-    for (const pkg of packages) {
-      const srcRoot = resolve(groupRoot, pkg, 'src')
-      walk(srcRoot, files)
+  const packagesRoot = resolve(root, 'packages')
+  for (const group of directories(packagesRoot)) {
+    for (const pkg of directories(resolve(packagesRoot, group))) {
+      walk(resolve(packagesRoot, group, pkg, 'src'), files)
     }
   }
   return files.sort()
 }
 
-function walk(dir: string, out: string[]): void {
+/** Immediate subdirectory names, or none when the path is not a directory. */
+function directories(dir: string): string[] {
+  if (!existsSync(dir)) return []
   let entries: Dirent[]
   try {
     entries = readdirSync(dir, { withFileTypes: true })
   } catch {
+    // Swallows only the race between existsSync and readdirSync (a package
+    // directory removed mid-sweep); readdirSync is the sole statement in the
+    // try, so no other failure can reach here.
+    return []
+  }
+  return entries.filter(entry => entry.isDirectory()).map(entry => entry.name)
+}
+
+function walk(dir: string, out: string[]): void {
+  if (!existsSync(dir)) return
+  let entries: Dirent[]
+  try {
+    entries = readdirSync(dir, { withFileTypes: true })
+  } catch {
+    // Same narrow race as `directories`: readdirSync is the only statement
+    // guarded, so this cannot mask a parse or assertion failure.
     return
   }
   for (const entry of entries) {
     const full = resolve(dir, entry.name)
-    if (entry.isDirectory()) {
-      walk(full, out)
-    } else if (entry.name.endsWith('.ts') && !entry.name.endsWith('.d.ts')) {
-      if (/^locales?(\.[\w-]+)?\.ts$/.test(entry.name) || dir.endsWith('/locales')) out.push(full)
-    }
+    if (entry.isDirectory()) walk(full, out)
+    else if (entry.name.endsWith('.ts') && !entry.name.endsWith('.d.ts')) out.push(full)
   }
 }
 
+/** One discovered dictionary: which file and export name declared it. */
+interface Dictionary {
+  /** Repo-relative declaring file. */
+  file: string
+  /** Export name, or the registration site for an inline literal. */
+  name: string
+  /** Declared keys, sorted. */
+  keys: string[]
+}
+
 /**
- * Keys of every top-level `export const <zh|en>...= { ... }` object literal,
- * read from the AST so the gate never executes package code.
- * @param file - absolute path of the dictionary module.
- * @returns exported dictionary name mapped to its declared keys.
+ * Keys of every top-level `export const <name> = { ... }` object literal whose
+ * name identifies a locale dictionary, plus inline `register(ns, locale, {...})`
+ * literals. Read from the AST so the gate never executes package code.
+ * @param file - absolute path of a candidate module.
+ * @returns discovered dictionaries, keyed by locale-bearing name.
  */
-function exportedDictionaries(file: string): Map<string, string[]> {
-  const source = ts.createSourceFile(file, readFileSync(file, 'utf8'), ts.ScriptTarget.ESNext, true)
-  const found = new Map<string, string[]>()
+function dictionariesIn(file: string): Dictionary[] {
+  const text = readFileSync(file, 'utf8')
+  // Cheap pre-filter: parsing every package source is wasteful, and a file
+  // with no locale token cannot declare a dictionary under any shape below.
+  if (!/\b(zh|en)\b/.test(text)) return []
+  const source = ts.createSourceFile(file, text, ts.ScriptTarget.ESNext, true)
+  const found: Dictionary[] = []
+  const rel = relative(file)
+
   for (const statement of source.statements) {
     if (!ts.isVariableStatement(statement)) continue
-    const exported = statement.modifiers?.some(m => m.kind === ts.SyntaxKind.ExportKeyword) === true
-    if (!exported) continue
+    if (statement.modifiers?.some(m => m.kind === ts.SyntaxKind.ExportKeyword) !== true) continue
     for (const decl of statement.declarationList.declarations) {
       if (!ts.isIdentifier(decl.name)) continue
-      const initializer = unwrap(decl.initializer)
-      if (initializer === undefined || !ts.isObjectLiteralExpression(initializer)) continue
-      const keys: string[] = []
-      for (const prop of initializer.properties) {
-        if (!ts.isPropertyAssignment(prop)) continue
-        if (ts.isIdentifier(prop.name) || ts.isStringLiteral(prop.name)) keys.push(prop.name.text)
-      }
-      found.set(decl.name.text, keys.sort())
+      const literal = unwrap(decl.initializer)
+      if (literal === undefined || !ts.isObjectLiteralExpression(literal)) continue
+      if (localeOf(decl.name.text) === undefined) continue
+      found.push({ file: rel, name: decl.name.text, keys: keysOf(literal) })
     }
   }
+
+  // Inline registrations: a `[['zh', {...}], ['en', {...}]]` pair handed to a
+  // registration loop in the plugin body. Both halves key off the enclosing
+  // array's line so they pair with each other and not across sites.
+  const visit = (node: ts.Node): void => {
+    if (ts.isArrayLiteralExpression(node) && node.elements.length === 2) {
+      const site = source.getLineAndCharacterOfPosition(node.getStart(source)).line + 1
+      for (const element of node.elements) {
+        if (!ts.isArrayLiteralExpression(element) || element.elements.length !== 2) continue
+        const [tag, dict] = element.elements
+        const literal = unwrap(dict)
+        if (tag === undefined || !ts.isStringLiteral(tag)) continue
+        if (literal === undefined || !ts.isObjectLiteralExpression(literal)) continue
+        if (tag.text !== 'zh' && tag.text !== 'en') continue
+        found.push({ file: rel, name: `${tag.text}@inline:${site}`, keys: keysOf(literal) })
+      }
+    }
+    ts.forEachChild(node, visit)
+  }
+  visit(source)
   return found
 }
 
+/** Declared property names of an object literal, sorted. */
+function keysOf(literal: ts.ObjectLiteralExpression): string[] {
+  const keys: string[] = []
+  for (const prop of literal.properties) {
+    if (!ts.isPropertyAssignment(prop)) continue
+    if (ts.isIdentifier(prop.name) || ts.isStringLiteral(prop.name)) keys.push(prop.name.text)
+  }
+  return keys.sort()
+}
+
 /** Look through `satisfies`/`as`/parenthesized wrappers to the literal. */
 function unwrap(node: ts.Expression | undefined): ts.Expression | undefined {
   let current = node
@@ -98,40 +159,90 @@ function unwrap(node: ts.Expression | undefined): ts.Expression | undefined {
   return current
 }
 
-/** Pair a `zh` export with the `en` export covering the same namespace. */
-function counterpart(name: string): string | undefined {
-  if (name === 'zh') return 'en'
-  if (name.startsWith('zh') && name.length > 2) return `en${name.slice(2)}`
-  if (name.endsWith('Zh')) return `${name.slice(0, -2)}En`
+/**
+ * The locale a dictionary name declares, and the namespace-ish remainder that
+ * identifies which pair it belongs to. `zh`/`en`, `zhSettings`/`enSettings`,
+ * and `settingsZh`/`settingsEn` are the shapes this repo uses.
+ * @param name - export name or synthetic inline name.
+ * @returns locale plus pair key, or undefined when the name names no locale.
+ */
+function localeOf(name: string): { locale: 'zh' | 'en'; pair: string } | undefined {
+  for (const locale of ['zh', 'en'] as const) {
+    const other = locale === 'zh' ? 'Zh' : 'En'
+    if (name === locale) return { locale, pair: '' }
+    if (name.startsWith(`${locale}@inline:`)) return { locale, pair: name.slice(name.indexOf(':')) }
+    if (name.startsWith(locale) && name.length > 2 && name[2] === name[2]?.toUpperCase()) {
+      return { locale, pair: name.slice(2) }
+    }
+    if (name.endsWith(other)) return { locale, pair: name.slice(0, -2) }
+  }
   return undefined
 }
 
 describe('shipped locale dictionaries', () => {
   it('declares the same keys in zh and en, so the single fallback locale always resolves', () => {
-    const modules = dictionaryModules()
-    // Guard the discovery itself: an empty sweep would pass every assertion
-    // below while checking nothing.
-    expect(modules.length).toBeGreaterThan(20)
+    const files = sourceFiles()
+    // Guard the discovery itself: an empty or narrowed sweep would pass every
+    // assertion below while checking nothing.
+    expect(files.length).toBeGreaterThan(500)
 
-    const mismatches: string[] = []
-    let comparedPairs = 0
-    for (const file of modules) {
-      const dicts = exportedDictionaries(file)
-      for (const [name, zhKeys] of dicts) {
-        const enName = counterpart(name)
-        if (enName === undefined) continue
-        const enKeys = dicts.get(enName)
-        if (enKeys === undefined) continue
-        comparedPairs++
-        const rel = file.slice(root.length)
-        const zhOnly = zhKeys.filter(key => !enKeys.includes(key))
-        const enOnly = enKeys.filter(key => !zhKeys.includes(key))
-        if (zhOnly.length > 0) mismatches.push(`${rel} ${name} has keys absent from ${enName}: ${zhOnly.join(', ')}`)
-        if (enOnly.length > 0) mismatches.push(`${rel} ${enName} has keys absent from ${name}: ${enOnly.join(', ')}`)
+    // Pair within a file first; a dictionary whose counterpart is not in the
+    // same module then pairs with a sibling in the same directory. Both shapes
+    // ship here: `locales/settings.ts` exports zh+en together, while
+    // `locales/zh.ts` + `locales/en.ts` split the common pair across files.
+    const perFile = new Map<string, Dictionary[]>()
+    for (const file of files) {
+      const dicts = dictionariesIn(file)
+      if (dicts.length > 0) perFile.set(relative(file), dicts)
+    }
+
+    const groups = new Map<string, Map<'zh' | 'en', Dictionary>>()
+    const place = (key: string, locale: 'zh' | 'en', dict: Dictionary): void => {
+      const slot = groups.get(key) ?? new Map<'zh' | 'en', Dictionary>()
+      if (slot.has(locale)) {
+        throw new Error(`two ${locale} dictionaries claim pair ${key}: ${slot.get(locale)?.file} and ${dict.file}`)
+      }
+      slot.set(locale, dict)
+      groups.set(key, slot)
+    }
+
+    for (const [rel, dicts] of perFile) {
+      for (const dict of dicts) {
+        const parsed = localeOf(dict.name)
+        if (parsed === undefined) continue
+        const sameFileCounterpart = dicts.some((other) => {
+          const otherParsed = localeOf(other.name)
+          return otherParsed !== undefined
+            && otherParsed.pair === parsed.pair
+            && otherParsed.locale !== parsed.locale
+        })
+        // Same-file pairs key by file so two pairs in one directory stay
+        // distinct; split pairs key by directory so siblings meet.
+        const key = sameFileCounterpart ? `${rel}::${parsed.pair}` : `${dirname(rel)}::${parsed.pair}`
+        place(key, parsed.locale, dict)
       }
     }
 
-    expect(comparedPairs).toBeGreaterThan(20)
-    expect(mismatches).toEqual([])
+    const problems: string[] = []
+    let comparedPairs = 0
+    for (const [key, slot] of [...groups].sort()) {
+      const zh = slot.get('zh')
+      const en = slot.get('en')
+      if (zh === undefined || en === undefined) {
+        const present = zh ?? en
+        problems.push(`${present?.file} declares ${present?.name} with no counterpart for pair ${key}`)
+        continue
+      }
+      comparedPairs++
+      const zhOnly = zh.keys.filter(k => !en.keys.includes(k))
+      const enOnly = en.keys.filter(k => !zh.keys.includes(k))
+      if (zhOnly.length > 0) problems.push(`${zh.file} ${zh.name} has keys absent from ${en.name}: ${zhOnly.join(', ')}`)
+      if (enOnly.length > 0) problems.push(`${en.file} ${en.name} has keys absent from ${zh.name}: ${enOnly.join(', ')}`)
+    }
+
+    // The shipped dictionary count only grows; a collapse means discovery or
+    // pairing broke, which would hide real asymmetry.
+    expect(comparedPairs).toBeGreaterThan(25)
+    expect(problems).toEqual([])
   })
 })