diff --git a/.gitignore b/.gitignore
index 0951cdd..48a6303 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,6 +46,7 @@ tests/.ipc.cjs
 tests/.ipc-channels.cjs
 tests/.log-sanitizer.cjs
 tests/.reserved-accelerators.cjs
+tests/.terminal-title.cjs
 release/
 
 # stray local test artifacts
diff --git a/AGENTS.md b/AGENTS.md
index e8ccbfd..c7a098e 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -7,10 +7,10 @@ Electron + electron-vite + React 终端工具（本地终端 / SSH / SFTP）。
 - 开发：`npm run dev`（主进程改动不热重建，需重启）
 - dev 实例使用独立用户数据目录 `%APPDATA%\OpenTerminal-dev` 与独立单实例锁（`src/main/index.ts` 顶部 `!app.isPackaged` 分支），窗口标题带 `(dev)`：**可与已安装的正式版同时运行，互不干扰**，也不会把测试设置/会话写进真实配置
 - 类型检查：`npm run typecheck`（tsconfig.node.json + tsconfig.web.json；只看渲染层可单跑 `npx tsc --noEmit -p tsconfig.web.json`）
-- 测试：`npm test`（**npm 生命周期先自动跑 `pretest` 做类型检查**，再 `node tests/build-bundles.cjs` 重建 esbuild bundle，然后依次跑可离线运行的 17 个测试：ssh-loopback、commands-store、connections-store、settings-store、local-path-grants、lock-store、lock-controller、lock-shortcuts、hl-split-smoke、hl-rules、reserved-accelerators、ipc-guard、updater-fallback、log-sanitizer、sftp-timeout、zmodem-e2e、ssh-session-e2e、sysinfo-e2e；真实服务器测试需 JD_* 凭据，不在此列）
+- 测试：`npm test`（**npm 生命周期先自动跑 `pretest` 做类型检查**，再 `node tests/build-bundles.cjs` 重建 esbuild bundle，然后依次跑可离线运行的 18 个测试：ssh-loopback、commands-store、connections-store、settings-store、local-path-grants、lock-store、lock-controller、lock-shortcuts、hl-split-smoke、hl-rules、reserved-accelerators、ipc-guard、updater-fallback、log-sanitizer、sftp-timeout、terminal-title、zmodem-e2e、ssh-session-e2e、sysinfo-e2e；真实服务器测试需 JD_* 凭据，不在此列）
 - 依赖分类规则：**只有 `src/main/`/`src/preload/` 实际 import 的包才能进 `dependencies`**（node-pty/ssh2/zmodem.js/font-list/electron-updater）；纯渲染层依赖一律 devDependencies（Vite 全量打包进 out/renderer，`externalizeDepsPlugin` 不作用渲染层）——这条让 asar 从 98MB 瘦到 8.1MB，加新依赖时别放错边
 - 下载量统计：`node scripts/download-stats.cjs`（Gitea + GitHub release 资产的 download_count 汇总；GitHub 优先直连、失败自动回退 `HTTPS_PROXY`/本地 7897；更新通道无计数接口不计入）
-- 打包：`npm run dist`（**生命周期先自动跑 `predist` → `npm test`，即类型检查 + 17 个离线测试全部通过后才 build/package**，typecheck 全程只跑一次；predist 末尾的 `npm install --package-lock-only` 会把 `package-lock.json` 根版本号对齐 `package.json`，**发布提交必须带上 package-lock.json**），产物在 `release/`（msi + exe + latest.yml + blockmap）
+- 打包：`npm run dist`（**生命周期先自动跑 `predist` → `npm test`，即类型检查 + 18 个离线测试全部通过后才 build/package**，typecheck 全程只跑一次；predist 末尾的 `npm install --package-lock-only` 会把 `package-lock.json` 根版本号对齐 `package.json`，**发布提交必须带上 package-lock.json**），产物在 `release/`（msi + exe + latest.yml + blockmap）
   - GitHub Actions：`.github/workflows/ci.yml` 在 windows-latest + Node 22 上跑 `npm ci` / `npm test`（含 pretest typecheck）/ `npm run build`，只做验证，不打包安装器、不发布
   - 国内网络需镜像：`ELECTRON_MIRROR=https://npmmirror.com/mirrors/electron/ ELECTRON_BUILDER_BINARIES_MIRROR=https://npmmirror.com/mirrors/electron-builder-binaries/ npm run dist`
 
@@ -70,6 +70,7 @@ Electron + electron-vite + React 终端工具（本地终端 / SSH / SFTP）。
 - `src/shared/reservedAccelerators.ts`：设置页录制器与主进程 `applyGlobalShortcut` **共用同一张保留键表**（Ctrl+L、Ctrl+=/-/0/PgUp/PgDn），两处分表曾漂移出洞，加新全局快捷键时两边自动一致
 - SFTP 操作有 per-op 超时（`sftp.ts` 的 `bounded()`：元数据 30s / 传输块 60s / open 10s），超时按 transport 错误驱逐半死通道并重试一次；`setSftpTimeouts`/`setUpdateTimeouts` 是**测试缝**，生产无调用者，别接设置项
 - `webPreferences` 显式写死 `contextIsolation: true / nodeIntegration: false / webSecurity: true`（`index.ts` 唯一窗口创建点），防默认值被将来改动
+- 终端标签自动标题（「终端 N」）是**存储的显示文本**（进布局模板/会话快照/广播注册），`src/shared/terminalTitle.ts` 负责两个方向：反解用**全部 4 语言**的 pattern（任何语言生成的都能认出编号），渲染用当前语言；语言切换/快照恢复/模板应用时 `retitleAutoTitles` 原地重渲染（SSH 面板标题是用户起的连接名，永不动）。需要指定语言渲染时用 i18n 的 `tFor(lang, key, vars)`
 
 ## 锁屏
 
diff --git a/docs/ROADMAP.md b/docs/ROADMAP.md
index b4e50cd..1f92c8c 100644
--- a/docs/ROADMAP.md
+++ b/docs/ROADMAP.md
@@ -146,7 +146,7 @@
 - [x] 归档脚本入 `scripts/`，`KEEP_TAG` 改必传参数
 - [x] `isPanicLockChord` 改判 `input.code`（物理键位，Dvorak/非拉丁布局正确）
 - [x] P3：设置页「更新通道」死控件移除、layoutMenu/IconRail memo + onOpenSettings useCallback、TerminalHandle 死 API 移除
-- [ ] 面板标题存已翻译字符串（切语言错位）——** deferred**：牵涉 5 个消费点 + 旧持久化数据兼容，另开一轮处理
+- [x] 面板标题存已翻译字符串（切语言错位）——✅ 已修：不改持久化格式，改多语言反解 + 语言切换/快照恢复/模板应用三处原地重渲染（`src/shared/terminalTitle.ts`，18 号测试 terminal-title）
 
 ## 工程约定（贯穿各阶段）
 
diff --git a/package.json b/package.json
index 8fed144..16c2e08 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "preview": "electron-vite preview",
     "typecheck": "tsc --noEmit -p tsconfig.node.json && tsc --noEmit -p tsconfig.web.json",
     "pretest": "npm run typecheck",
-    "test": "node tests/build-bundles.cjs && node tests/ssh-loopback.mjs && node tests/commands-store.mjs && node tests/connections-store.mjs && node tests/settings-store.mjs && node tests/local-path-grants.mjs && node tests/lock-store.mjs && node tests/lock-controller.mjs && node tests/lock-shortcuts.mjs && node tests/reserved-accelerators.mjs && node tests/ipc-guard.mjs && node tests/updater-fallback.mjs && node tests/log-sanitizer.mjs && node tests/sftp-timeout.mjs && node tests/.hl-split-smoke.cjs && node tests/.hl-rules.cjs && node tests/zmodem-e2e.mjs && node tests/ssh-session-e2e.mjs && node tests/sysinfo-e2e.mjs",
+    "test": "node tests/build-bundles.cjs && node tests/ssh-loopback.mjs && node tests/commands-store.mjs && node tests/connections-store.mjs && node tests/settings-store.mjs && node tests/local-path-grants.mjs && node tests/lock-store.mjs && node tests/lock-controller.mjs && node tests/lock-shortcuts.mjs && node tests/reserved-accelerators.mjs && node tests/.terminal-title.cjs && node tests/ipc-guard.mjs && node tests/updater-fallback.mjs && node tests/log-sanitizer.mjs && node tests/sftp-timeout.mjs && node tests/.hl-split-smoke.cjs && node tests/.hl-rules.cjs && node tests/zmodem-e2e.mjs && node tests/ssh-session-e2e.mjs && node tests/sysinfo-e2e.mjs",
     "predist": "npm test && npm install --package-lock-only",
     "dist": "electron-vite build && electron-builder --win msi nsis",
     "dist:dir": "electron-vite build && electron-builder --win --dir"
diff --git a/src/renderer/src/workspace/Workspace.tsx b/src/renderer/src/workspace/Workspace.tsx
index d6693ae..453c350 100644
--- a/src/renderer/src/workspace/Workspace.tsx
+++ b/src/renderer/src/workspace/Workspace.tsx
@@ -28,6 +28,7 @@ import 'dockview-react/dist/styles/dockview.css'
 
 import { connectPromptFor, type HostKeyPromptEvent, type SshConnection, type SshSecretOverride } from '@shared/connections'
 import { t } from '@shared/i18n'
+import { nextTerminalTitle, retitleAutoTitles } from '@shared/terminalTitle'
 import { ConnectionSidebar } from '../connections/ConnectionSidebar'
 import type { ConnectionSidebarHandle } from '../connections/ConnectionSidebar'
 import { ConnectFlow } from './ConnectFlow'
@@ -129,31 +130,6 @@ function restoreLayoutSnapshot(api: DockviewApi | undefined, snapshot: Serialize
   }
 }
 
-/**
- * "终端 N" titles fill the lowest free number among live panels: closing a
- * pane frees its number for the next new terminal, and a session restore can
- * no longer leave the numbering behind (the old in-memory counter restarted
- * at zero on launch and produced duplicate titles).
- */
-function nextTerminalTitle(existing: Iterable<string | undefined>): string {
-  const used = new Set<number>()
-  // The pattern is translated, so the number is read back through that same
-  // pattern (the `{n}` placeholder marks the digits) instead of a fixed one.
-  const [head, tail] = t('workspace.tab.terminalTitle', { n: '\u0000' }).split('\u0000')
-  const matcher = new RegExp(`^${escapeRegExp(head)}(\\d+)${escapeRegExp(tail ?? '')}$`)
-  for (const title of existing) {
-    const n = title?.match(matcher)?.[1]
-    if (n) used.add(Number(n))
-  }
-  let n = 1
-  while (used.has(n)) n++
-  return t('workspace.tab.terminalTitle', { n })
-}
-
-function escapeRegExp(text: string): string {
-  return text.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
-}
-
 function sessionIdOf(panel: IDockviewPanel | undefined): string | undefined {
   return (panel?.params as TerminalParams | undefined)?.sessionId
 }
@@ -457,6 +433,32 @@ export default function Workspace({ onOpenSettings }: WorkspaceProps): React.JSX
     setModeCounts((prev) => (prev.terminal === t && prev.ssh === s ? prev : { terminal: t, ssh: s }))
   }, [])
 
+  /**
+   * Re-render every auto-numbered tab title in the active language, keeping its
+   * number. Idempotent — a title already in the active language is left alone.
+   *
+   * Titles are stored display text (they ride along in layout templates, the
+   * session snapshot and the broadcast registry) and outlive a language switch,
+   * so without this a pane keeps the wording of the language it was opened in.
+   *
+   * SSH panes are excluded: their title is the connection name the user typed,
+   * and a connection named "Terminal 3" must not be renamed behind their back.
+   *
+   * `setTitle` fires dockview's title-change event, which is all the rest needs:
+   * `TerminalPanel` re-registers the broadcast title, the tab component
+   * re-renders, the sidebar list refreshes and the snapshot save is scheduled
+   * (a panel title change forwards into the dockview's layout-change event).
+   */
+  const retitleAutoPanels = useCallback((): void => {
+    retitleAutoTitles(
+      [terminalApiRef.current, sshApiRef.current].flatMap((api) =>
+        (api?.panels ?? []).filter(
+          (panel) => (panel.params as TerminalParams | undefined)?.sessionKind !== 'ssh'
+        )
+      )
+    )
+  }, [])
+
   /** Focus a local terminal panel from the sidebar (terminal dockview). */
   const onFocusPanel = useCallback((panelId: string): void => {
     const panel = terminalApiRef.current?.getPanel(panelId)
@@ -996,6 +998,11 @@ export default function Workspace({ onOpenSettings }: WorkspaceProps): React.JSX
       const renames = new Map([...terminalLayout.renames, ...sshLayout.renames])
       await rebindSessionPanels(terminal, snapshot, true, renames)
       await rebindSessionPanels(ssh, snapshot, true, renames)
+      // A snapshot is written in whatever language was active at the time, so
+      // render its auto titles in the current language before anything compares
+      // them: the dedup below then sees "终端 3" and "Terminal 3" as the one
+      // collision they are instead of letting both through.
+      retitleAutoPanels()
       // Retitle duplicates left over from the old counter bug (the snapshot it
       // wrote keeps colliding titles forever otherwise): the first panel keeps
       // the title, later ones get the lowest free number.
@@ -1006,13 +1013,13 @@ export default function Workspace({ onOpenSettings }: WorkspaceProps): React.JSX
       const seenTitles = new Set<string>()
       for (const p of [...(terminal?.panels ?? []), ...(ssh?.panels ?? [])]) {
         if ((p.params as TerminalParams | undefined)?.sessionKind === 'ssh') continue
-        const t = p.title ?? ''
-        if (!t) continue
-        if (seenTitles.has(t)) {
+        const title = p.title ?? ''
+        if (!title) continue
+        if (seenTitles.has(title)) {
           const fresh = nextTerminalTitle(seenTitles)
           p.setTitle(fresh)
           seenTitles.add(fresh)
-        } else seenTitles.add(t)
+        } else seenTitles.add(title)
       }
       lastLocalCwdRef.current = snapshot.lastLocalCwd ?? lastLocalCwdRef.current
       useWorkspaceModeStore.getState().setMode(snapshot.mode)
@@ -1020,7 +1027,7 @@ export default function Workspace({ onOpenSettings }: WorkspaceProps): React.JSX
       recomputeLocalPanels()
       return true
     },
-    [rebindSessionPanels, recountAll, recomputeLocalPanels]
+    [rebindSessionPanels, recountAll, recomputeLocalPanels, retitleAutoPanels]
   )
 
   const handleApplyTemplate = useCallback(
@@ -1119,6 +1126,11 @@ export default function Workspace({ onOpenSettings }: WorkspaceProps): React.JSX
       if (terminalApiRef.current) await rebindRestoredPanels(terminalApiRef.current)
       if (sshApiRef.current) await rebindRestoredPanels(sshApiRef.current)
 
+      // A template carries the tab titles it was saved with, which may be in
+      // another language (or written by a build whose language the user has
+      // since switched away from).
+      retitleAutoPanels()
+
       // Old sessions are unreachable after the layout swap — kill them.
       for (const sid of previousSessions) killSession(sid)
       recountAll()
@@ -1126,7 +1138,7 @@ export default function Workspace({ onOpenSettings }: WorkspaceProps): React.JSX
       const mode = useWorkspaceModeStore.getState().mode
       activePanelRef.current = apiOfMode(mode, terminalApiRef.current, sshApiRef.current)?.activePanel
     },
-    [killSession, message, rebindRestoredPanels, recountAll, recomputeLocalPanels]
+    [killSession, message, rebindRestoredPanels, recountAll, recomputeLocalPanels, retitleAutoPanels]
   )
 
   const handleDeleteTemplate = useCallback(async (meta: LayoutMetaLike): Promise<void> => {
@@ -1156,6 +1168,20 @@ export default function Workspace({ onOpenSettings }: WorkspaceProps): React.JSX
   // are translated at build time, so `language` has to be a dependency or a
   // language switch would leave stale menu text behind.
   const language = useSettingsStore((s) => s.settings.system.language)
+
+  // Auto tab titles are stored display text, so they have to be re-rendered on
+  // a language switch — the rest of the UI re-renders itself. Skipped on mount
+  // (a boot pass has not restored any panel yet, and a restored title is
+  // retitled by the pass itself) and on every settings echo that leaves the
+  // language untouched, which is the common case.
+  const lastLanguageRef = useRef<string | undefined>(undefined)
+  useEffect(() => {
+    if (lastLanguageRef.current === language) return
+    const changed = lastLanguageRef.current !== undefined
+    lastLanguageRef.current = language
+    if (changed) retitleAutoPanels()
+  }, [language, retitleAutoPanels])
+
   const layoutMenu = useMemo<MenuProps>(
     () => ({
       items: [
diff --git a/src/shared/i18n/index.ts b/src/shared/i18n/index.ts
index 5cb361f..5482097 100644
--- a/src/shared/i18n/index.ts
+++ b/src/shared/i18n/index.ts
@@ -90,7 +90,18 @@ export function onLanguageChange(cb: (lang: Language) => void): () => void {
 
 /** Translate `key`; `{name}` placeholders are filled from `vars`. */
 export function t(key: string, vars?: Record<string, string | number>): string {
-  const raw = lookup(DICTS[current], key) ?? lookup(DICTS[DEFAULT_LANGUAGE], key) ?? key
+  return tFor(current, key, vars)
+}
+
+/**
+ * Translate `key` as if `lang` were the active language, with the same
+ * fallback chain as `t`. Needed where a string has to be produced for a
+ * language other than the one being rendered: stored display text (terminal
+ * tab titles) is re-rendered on a language switch, and the language that text
+ * was written in has to be readable back out of it.
+ */
+export function tFor(lang: Language, key: string, vars?: Record<string, string | number>): string {
+  const raw = lookup(DICTS[lang], key) ?? lookup(DICTS[DEFAULT_LANGUAGE], key) ?? key
   if (!vars) return raw
   return raw.replace(/\{(\w+)\}/g, (match, name: string) =>
     vars[name] === undefined ? match : String(vars[name])
diff --git a/src/shared/terminalTitle.ts b/src/shared/terminalTitle.ts
new file mode 100644
index 0000000..b0568a0
--- /dev/null
+++ b/src/shared/terminalTitle.ts
@@ -0,0 +1,139 @@
+/**
+ * Auto-generated local-terminal tab titles ("终端 3", "Terminal 3", …).
+ *
+ * A tab title is stored DISPLAY text, not data: dockview serializes it into
+ * layout templates, the workspace writes it into the session snapshot, and the
+ * broadcast registry keeps it. It used to be produced from the pattern of the
+ * *active* language and read back through that same pattern, so a title written
+ * before a language switch was neither countable (numbering restarted and
+ * produced duplicates) nor re-renderable (it stayed in the old language).
+ *
+ * The two directions are therefore asymmetric:
+ *   - resolution runs over EVERY language's pattern, so an auto title is
+ *     recognized no matter which language wrote it;
+ *   - rendering uses the active language, so a switch re-renders it in place.
+ *
+ * A title matching no pattern was typed by the user and is never touched.
+ *
+ * Pure module (no Electron, no React, no browser surface) so plain Node can
+ * table-test it; the same shape as `reservedAccelerators.ts`.
+ */
+
+import { LANGUAGES, t, tFor } from './i18n'
+
+const TITLE_KEY = 'workspace.tab.terminalTitle'
+
+/** Sentinel for "the number goes here", so the rendered pattern can be split
+ *  into its literal head and tail. Cannot occur in a dictionary. */
+const MARK = '\u0000'
+
+function escapeRegExp(text: string): string {
+  return text.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+}
+
+/**
+ * Split a rendered pattern into the text before and after the number.
+ * `undefined` when the dictionary has no `{n}` at all (a missing key falls back
+ * to the key itself) or more than one — such a language cannot title a pane.
+ */
+function splitPattern(rendered: string): { head: string; tail: string } | undefined {
+  const parts = rendered.split(MARK)
+  if (parts.length !== 2) return undefined
+  return { head: parts[0], tail: parts[1] }
+}
+
+/**
+ * Every language's pattern, compiled once: the dictionaries are static for the
+ * process's lifetime. Duplicates are dropped — a dictionary missing the key
+ * falls back to zh-CN and would otherwise be matched twice.
+ */
+const PATTERNS: RegExp[] = (() => {
+  const out: RegExp[] = []
+  const seen = new Set<string>()
+  for (const { value } of LANGUAGES) {
+    const parts = splitPattern(tFor(value, TITLE_KEY, { n: MARK }))
+    if (!parts) continue
+    const key = `${parts.head}\u0001${parts.tail}`
+    if (seen.has(key)) continue
+    seen.add(key)
+    // Both literals are anchored and matched exactly: "终端 3 号" and
+    // "终端机 3" are user titles, not auto ones. The digits exclude a leading
+    // zero — the app renders `String(n)` — so "Terminal 007" stays a user
+    // title instead of being renamed to "Terminal 7".
+    out.push(new RegExp(`^${escapeRegExp(parts.head)}([1-9]\\d*)${escapeRegExp(parts.tail)}$`))
+  }
+  return out
+})()
+
+/**
+ * The number an auto title carries, in whichever language wrote it, or
+ * `undefined` when the title is not an auto title.
+ */
+export function autoTerminalTitleNumber(title: string): number | undefined {
+  if (!title) return undefined
+  for (const matcher of PATTERNS) {
+    const found = matcher.exec(title)
+    if (found) return Number(found[1])
+  }
+  return undefined
+}
+
+/** The auto title for `n` in the active language. */
+export function renderTerminalTitle(n: number): string {
+  return t(TITLE_KEY, { n })
+}
+
+/**
+ * The auto title for the lowest free number among `existing`, in the active
+ * language. Numbers occupied in ANY language count as used, so a pane that
+ * still carries an old-language title keeps its number reserved.
+ *
+ * Closing a pane frees its number for the next new terminal, and a session
+ * restore can no longer leave the numbering behind (the old in-memory counter
+ * restarted at zero on launch and produced duplicate titles).
+ */
+export function nextTerminalTitle(existing: Iterable<string | undefined>): string {
+  const used = new Set<number>()
+  for (const title of existing) {
+    if (!title) continue
+    const n = autoTerminalTitleNumber(title)
+    if (n !== undefined) used.add(n)
+  }
+  let n = 1
+  while (used.has(n)) n++
+  return renderTerminalTitle(n)
+}
+
+/** Just enough of a dockview panel for {@link retitleAutoTitles} — the real
+ *  `IDockviewPanel` satisfies this structurally, so no adapter is needed. */
+export interface RetitlePanel {
+  readonly title: string | undefined
+  setTitle(title: string): void
+}
+
+/**
+ * Re-render `panels`' auto titles in the active language, keeping each number;
+ * returns how many were rewritten.
+ *
+ * Called on a language switch (the rest of the UI re-renders itself) and after
+ * a layout/snapshot restore (which brings back titles stored under some older
+ * language). A panel whose title matches no language's pattern was named by the
+ * user and is left exactly as it is; one whose title already reads correctly is
+ * skipped, so this is safe to run on every settings echo.
+ *
+ * The caller decides which panels are eligible: an SSH pane is titled with the
+ * connection name the user typed, so a connection called "Terminal 3" must not
+ * be renamed behind their back.
+ */
+export function retitleAutoTitles(panels: Iterable<RetitlePanel>): number {
+  let changed = 0
+  for (const panel of panels) {
+    const n = autoTerminalTitleNumber(panel.title ?? '')
+    if (n === undefined) continue
+    const next = renderTerminalTitle(n)
+    if (next === panel.title) continue
+    panel.setTitle(next)
+    changed++
+  }
+  return changed
+}
diff --git a/tests/build-bundles.cjs b/tests/build-bundles.cjs
index bdb3193..6f4c977 100644
--- a/tests/build-bundles.cjs
+++ b/tests/build-bundles.cjs
@@ -46,6 +46,9 @@ const BUNDLES = [
   // Reserved-accelerator table shared by the settings recorder and main's
   // registration guard: pure, table-tested.
   { entry: 'src/shared/reservedAccelerators.ts', out: 'tests/.reserved-accelerators.cjs' },
+  // Auto terminal-tab titles: the pattern table is shared by the renderer's
+  // numbering and its language-switch retitle pass. Pure + dictionary-only.
+  { entry: 'tests/terminal-title.mjs', out: 'tests/.terminal-title.cjs' },
   // Update service: feed probe/fallback. `electron-updater` is aliased to a
   // stub (the real package boots Electron), and the shell half (tray.ts) pulls
   // a `?asset` import, hence LOADERS.
diff --git a/tests/terminal-title.mjs b/tests/terminal-title.mjs
new file mode 100644
index 0000000..c491dcd
--- /dev/null
+++ b/tests/terminal-title.mjs
@@ -0,0 +1,173 @@
+/**
+ * Auto terminal-title self-test (terminal-title.mjs).
+ *
+ * A local terminal's tab title is stored DISPLAY text — it rides along in
+ * layout templates, the session snapshot and the broadcast registry — so it
+ * outlives the language it was written in. `src/shared/terminalTitle.ts` is the
+ * one place that reads the number back out of such a title and that renders a
+ * fresh one, and both directions have to agree with all four dictionaries:
+ *
+ *   - a title written in ANY language resolves to its number, so a workspace
+ *     created in 简体中文 keeps counting correctly after the user switches to
+ *     日本語 (and the numbers fill the lowest free gap);
+ *   - rendering follows the ACTIVE language, which is what makes a language
+ *     switch re-render "终端 3" as "Terminal 3";
+ *   - a title that matches no language's pattern is the user's own and must
+ *     never be resolved (a false positive would rename it on a language switch).
+ *
+ * The expected patterns are written out here rather than read from the module
+ * under test, so a dictionary that drifts from both would fail instead of
+ * agreeing with itself.
+ *
+ * Build: node tests/build-bundles.cjs
+ * Run:   node tests/.terminal-title.cjs   (must exit 0)
+ */
+import {
+  autoTerminalTitleNumber,
+  nextTerminalTitle,
+  renderTerminalTitle,
+  retitleAutoTitles
+} from '../src/shared/terminalTitle.ts'
+import { setLanguage, t } from '../src/shared/i18n/index.ts'
+
+let failed = 0
+const ok = (cond, msg) => {
+  console.log(`  ${cond ? 'ok' : 'FAIL'}: ${msg}`)
+  if (!cond) failed += 1
+}
+
+const LANGUAGES = ['zh-CN', 'zh-TW', 'en', 'ja']
+
+const PATTERN = {
+  'zh-CN': '终端 {n}',
+  'zh-TW': '終端機 {n}',
+  en: 'Terminal {n}',
+  ja: 'ターミナル {n}'
+}
+
+const title = (lang, n) => PATTERN[lang].replace('{n}', String(n))
+
+console.log('the four dictionaries still carry the patterns this table is built from')
+for (const lang of LANGUAGES) {
+  setLanguage(lang)
+  ok(
+    t('workspace.tab.terminalTitle', { n: 7 }) === title(lang, 7),
+    `${lang}: ${JSON.stringify(title(lang, 7))}`
+  )
+}
+
+console.log('rendering follows the ACTIVE language')
+for (const lang of LANGUAGES) {
+  setLanguage(lang)
+  ok(renderTerminalTitle(3) === title(lang, 3), `${lang}: renderTerminalTitle(3) = ${JSON.stringify(title(lang, 3))}`)
+  setLanguage(lang)
+  ok(nextTerminalTitle([]) === title(lang, 1), `${lang}: an empty workspace starts at ${JSON.stringify(title(lang, 1))}`)
+}
+
+console.log('every writer/reader language pair resolves')
+for (const writer of LANGUAGES) {
+  for (const reader of LANGUAGES) {
+    setLanguage(reader)
+    const written = title(writer, 12)
+    ok(
+      autoTerminalTitleNumber(written) === 12,
+      `${writer} title resolves while the UI is ${reader}: ${JSON.stringify(written)}`
+    )
+  }
+}
+
+console.log('numbering is language-independent, so a switch keeps the count')
+setLanguage('en')
+ok(
+  nextTerminalTitle(['终端 1', '終端機 2', 'Terminal 3', 'ターミナル 4']) === 'Terminal 5',
+  'one title per language still occupies its own number'
+)
+ok(nextTerminalTitle(['终端 3']) === 'Terminal 1', 'the lowest free number wins, not the highest used')
+ok(nextTerminalTitle(['终端 1', 'Terminal 2']) === 'Terminal 3', 'the first gap is filled')
+ok(nextTerminalTitle(['终端 2', 'Terminal 3']) === 'Terminal 1', 'a hole below the used range is filled')
+ok(nextTerminalTitle(['Terminal 5']) === 'Terminal 1', 'a lone high number does not push the counter up')
+setLanguage('ja')
+ok(nextTerminalTitle(['终端 3']) === 'ターミナル 1', 'numbering renders in the language that is active now')
+
+console.log('user-authored titles are never resolved')
+const notAuto = [
+  // The match is anchored and both literals must be exact.
+  '终端机 3', // 简体 "machine": one character away from 繁體 "終端機"
+  '終端機3', // missing the space
+  '终端 3 号',
+  '终端  3', // double space
+  ' 终端 3', // leading space
+  '终端 3 ', // trailing space
+  'My Terminal 4',
+  'Terminal',
+  'Terminal ',
+  'Terminal #3',
+  'x Terminal 3',
+  'Terminal 3x',
+  'ターミナル 3 番',
+  'Terminal 007', // the app never renders leading zeros
+  '终端 -3',
+  '终端 3.5',
+  '',
+  '終端機 ٣' // Arabic-Indic digit
+]
+for (const s of notAuto) {
+  const n = autoTerminalTitleNumber(s)
+  ok(n === undefined, `not auto: ${JSON.stringify(s)} (got ${String(n)})`)
+}
+
+console.log('degenerate input neither throws nor resolves')
+for (const s of [undefined, null, 'Terminal 3'.repeat(400)]) {
+  let threw = false
+  let n
+  try {
+    n = autoTerminalTitleNumber(s)
+  } catch {
+    threw = true
+  }
+  ok(!threw && n === undefined, `safe on ${JSON.stringify(s)?.slice(0, 24) ?? String(s)}`)
+}
+
+console.log('a language switch retitles exactly the auto titles')
+/** Minimal stand-in for a dockview panel, so the retitle pass runs unchanged. */
+const fakePanel = (title) => {
+  const panel = { title, written: [] }
+  panel.setTitle = (next) => {
+    panel.written.push(next)
+    panel.title = next
+  }
+  return panel
+}
+const runRetitle = (lang, titles) => {
+  setLanguage(lang)
+  const panels = titles.map(fakePanel)
+  const changed = retitleAutoTitles(panels)
+  return { changed, titles: panels.map((p) => p.title), writes: panels.map((p) => p.written.length) }
+}
+
+ok(
+  JSON.stringify(runRetitle('en', ['终端 1', '終端機 2', 'Terminal 3', 'ターミナル 4'])) ===
+    JSON.stringify({ changed: 3, titles: ['Terminal 1', 'Terminal 2', 'Terminal 3', 'Terminal 4'], writes: [1, 1, 0, 1] }),
+  'each old-language title is rewritten; one already in the active language is not'
+)
+ok(
+  JSON.stringify(runRetitle('ja', ['终端 3', 'My Terminal 4', 'x Terminal 5', 'Terminal'])) ===
+    JSON.stringify({ changed: 1, titles: ['ターミナル 3', 'My Terminal 4', 'x Terminal 5', 'Terminal'], writes: [1, 0, 0, 0] }),
+  'user titles survive a language switch untouched'
+)
+ok(
+  JSON.stringify(runRetitle('zh-TW', ['Terminal 7'])) ===
+    JSON.stringify({ changed: 1, titles: ['終端機 7'], writes: [1] }),
+  'the number is preserved across the switch'
+)
+ok(runRetitle('en', []).changed === 0, 'an empty panel list is a no-op')
+ok(
+  runRetitle('en', ['终端 1', 'Terminal 1']).changed === 1,
+  'two spellings of number 1 are re-rendered to one title without renumbering'
+)
+
+if (failed > 0) {
+  console.error(`\n[terminal-title] ${failed} check(s) FAILED`)
+  process.exit(1)
+}
+console.log('\n[terminal-title] ALL CHECKS PASSED')