diff --git a/docs/contracts/Host-v1契约.md b/docs/contracts/Host-v1契约.md
index 3d785e5..0fe80f6 100644
--- a/docs/contracts/Host-v1契约.md
+++ b/docs/contracts/Host-v1契约.md
@@ -1,6 +1,6 @@
 # Rust Host v1 预览契约
 
-状态：Rust 核心测试、clippy、Tauri 工程编译及 Windows GNU 开发可执行文件构建通过。**尚无可发布安装包，未完成原生界面实测**。不将开发构建等同 D01–D08 全部通过。
+状态：Rust 核心测试、clippy、Tauri 工程编译及 Windows GNU 开发可执行文件构建通过。**尚无可发布安装包，新标题栏仍待原生界面实测**。不将开发构建等同 D01–D08 全部通过。
 
 ## 命令
 
@@ -33,6 +33,6 @@ OS 文件锁配合 Rust Mutex 维持单实例 Vault 写入。Web `serialized_vau
 
 ## 前端与发布
 
-Web 模式沿用现有服务。Tauri Workspace Service 调用原生命令；AI Core 未接通时明确返回 CORE_UNAVAILABLE。关闭请求先尝试保存；冲突或保存失败时保持窗口。原生“导入为笔记属性”菜单已创建但禁用，转换事务尚未完成。
+Web 模式沿用现有服务。Tauri Workspace Service 调用原生命令；AI Core 未接通时明确返回 CORE_UNAVAILABLE。桌面窗口关闭系统装饰，统一由应用标题栏提供拖动、最小化、最大化/还原及关闭；窗口命令只授予本地 `main` WebView。关闭请求先尝试保存，冲突或保存失败时保持窗口。原生“导入为笔记属性”菜单仅在源码模式和已打开笔记时启用，转换作为单次编辑器历史事务执行。
 
-`bundle.active=false`，无自动更新、无签名安装包。开发命令为前端 `pnpm dev` 与 `cargo run --features desktop`；前端生产构建后可 `cargo build --features desktop --release`，仍只构建预览程序。需要对应平台 C++ 工具链和 WebView；本次 Windows 使用工作树内隔离 GNU/LLVM 工具链，不替代官方 MSVC 或其他平台构建。
+`bundle.active=false`，无自动更新、无签名安装包。开发命令为前端 `pnpm dev` 与 `cargo run --features desktop`；前端生产构建后可 `cargo build --features desktop --release`，仍只构建预览程序。需要对应平台 C++ 工具链和 WebView；本次 Windows 已使用系统 `x86_64-pc-windows-gnu` 工具链构建，仍不替代 MSVC 或其他平台验证。
diff --git a/docs/development/第三阶段实施与验收记录.md b/docs/development/第三阶段实施与验收记录.md
index 23f90b0..956564a 100644
--- a/docs/development/第三阶段实施与验收记录.md
+++ b/docs/development/第三阶段实施与验收记录.md
@@ -17,7 +17,7 @@
 ## 已执行验证
 
 - 后端：887 项 pytest 通过；新增 Web/桌面单写入者门禁测试。
-- 前端：87 个文件、471 项 Vitest 通过；TypeScript 检查与 Vite 生产构建通过，保留既有大 chunk 提示。
+- 前端：88 个文件、473 项 Vitest 通过；TypeScript 检查与 Vite 生产构建通过，保留既有大 chunk 提示。桌面标题栏窗口操作使用 Tauri capability，Web 模式不显示伪窗口按钮。
 - Sync v1：18 项隔离测试通过，Windows / Python 3.13.9 / SQLite / 磁盘对象 Fixture。包括双线程并发 CAS；不是 PostgreSQL 多 Worker 压测。
 - Community v1：13 项隔离测试通过；前端使用 Python 生成的真实 Ed25519 向量互验。
 - Rust：系统 `rustc/cargo 1.98.1`（`x86_64-pc-windows-gnu`）下，5 项文件恢复测试、rustfmt、clippy `-D warnings` 和 Tauri desktop 开发构建通过。没有安装包或实机 UI 证据。
diff --git a/frontend/src-tauri/capabilities/main.json b/frontend/src-tauri/capabilities/main.json
index ab5c673..280df55 100644
--- a/frontend/src-tauri/capabilities/main.json
+++ b/frontend/src-tauri/capabilities/main.json
@@ -18,6 +18,10 @@
     "allow-workspace-recent",
     "allow-workspace-revoke",
     "core:window:allow-destroy",
+    "core:window:allow-close",
+    "core:window:allow-minimize",
+    "core:window:allow-toggle-maximize",
+    "core:window:allow-start-dragging",
     "allow-editor-capabilities"
   ]
 }
diff --git a/frontend/src-tauri/tauri.conf.json b/frontend/src-tauri/tauri.conf.json
index 9c82cae..d5d2d23 100644
--- a/frontend/src-tauri/tauri.conf.json
+++ b/frontend/src-tauri/tauri.conf.json
@@ -10,7 +10,7 @@
     "frontendDist": "../dist"
   },
   "app": {
-    "windows": [{"label": "main", "title": "NotesAgent Preview", "width": 1200, "height": 800, "minWidth": 640, "minHeight": 480}],
+    "windows": [{"label": "main", "title": "NotesAgent Preview", "width": 1200, "height": 800, "minWidth": 640, "minHeight": 480, "decorations": false}],
     "security": {
       "csp": "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; font-src 'self' data:; connect-src ipc: http://ipc.localhost; frame-src 'self' blob:; object-src 'none'; base-uri 'self'",
       "capabilities": ["main"]
diff --git a/frontend/src/App.vue b/frontend/src/App.vue
index 547ed72..06f082e 100644
--- a/frontend/src/App.vue
+++ b/frontend/src/App.vue
@@ -2,17 +2,29 @@
 import { computed } from 'vue'
 import { useRoute } from 'vue-router'
 import AppShell from '@/components/common/AppShell.vue'
+import TitleBar from '@/components/common/TitleBar.vue'
+import { isDesktop } from '@/services/platform/desktop'
 
 const route = useRoute()
 const isVaultEntry = computed(() => route.path === '/')
+const desktop = isDesktop()
 </script>
 
 <template>
-  <AppShell v-if="!isVaultEntry">
+  <div v-if="isVaultEntry" class="entry-shell">
+    <TitleBar v-if="desktop" />
+    <router-view />
+  </div>
+  <AppShell v-else>
     <router-view />
   </AppShell>
-  <router-view v-else />
 </template>
 
 <style scoped>
+.entry-shell {
+  display: flex;
+  flex-direction: column;
+  width: 100vw;
+  height: 100vh;
+}
 </style>
diff --git a/frontend/src/components/common/TitleBar.vue b/frontend/src/components/common/TitleBar.vue
index 3d7a9f3..da5819a 100644
--- a/frontend/src/components/common/TitleBar.vue
+++ b/frontend/src/components/common/TitleBar.vue
@@ -7,11 +7,14 @@ import { useThemeStore } from '@/stores/theme'
 import { Moon, Sunny } from '@element-plus/icons-vue'
 import AppIcon from './AppIcon.vue'
 import { t } from '@/i18n'
+import { isDesktop } from '@/services/platform/desktop'
+import { minimizeWindow, requestWindowClose, toggleMaximizeWindow } from '@/services/platform/windowControls'
 
 const route = useRoute()
 const workspaceStore = useWorkspaceStore()
 const editorStore = useEditorStore()
 const themeStore = useThemeStore()
+const desktop = isDesktop()
 
 const pageTitle = computed(() => {
   const name = route.name as string
@@ -25,6 +28,11 @@ const pageTitle = computed(() => {
     plugins: t('Plugin 与 MCP', 'Plugins and MCP'),
     themes: t('主题管理', 'Theme Management'),
     settings: t('设置', 'Settings'),
+    'vault-entry': t('选择知识库', 'Select Knowledge Base'),
+    community: t('社区目录', 'Community Catalog'),
+    benchmarks: 'Benchmark',
+    logs: t('运行日志', 'Operation Logs'),
+    media: t('音视频转写', 'Media Transcription'),
   }
   return titles[name] || 'NotesAgent'
 })
@@ -38,32 +46,36 @@ const currentFileName = computed(() => {
 })
 
 const isDirty = computed(() => editorStore.saveStatus === 'dirty' || editorStore.saveStatus === 'conflict')
+
+function toggleFromTitlebar(event: MouseEvent) {
+  if (desktop && !(event.target as HTMLElement).closest('button')) void toggleMaximizeWindow()
+}
 </script>
 
 <template>
-  <div class="titlebar">
-    <div class="titlebar-left">
-      <span class="vault-name">{{ workspaceStore.vaultName }}</span>
-      <span class="title-separator">/</span>
-      <span class="file-name" :class="{ dirty: isDirty }">
+  <header class="titlebar" :class="{ desktop }" data-tauri-drag-region @dblclick="toggleFromTitlebar">
+    <div class="titlebar-left" data-tauri-drag-region>
+      <span v-if="workspaceStore.vaultName" class="vault-name" data-tauri-drag-region>{{ workspaceStore.vaultName }}</span>
+      <span v-if="workspaceStore.vaultName" class="title-separator" data-tauri-drag-region>/</span>
+      <span class="file-name" :class="{ dirty: isDirty }" data-tauri-drag-region>
         {{ currentFileName }}
         <span v-if="isDirty" class="dirty-dot" />
       </span>
     </div>
-    <div class="titlebar-center">
-      <span class="app-name">NotesAgent</span>
+    <div class="titlebar-center" data-tauri-drag-region>
+      <span class="app-name" data-tauri-drag-region>NotesAgent</span>
     </div>
     <div class="titlebar-right">
       <button class="icon-btn" @click="themeStore.toggleTheme()" :title="themeStore.isDark ? t('切换浅色主题', 'Switch to light theme') : t('切换深色主题', 'Switch to dark theme')">
         <AppIcon :icon="themeStore.isDark ? Sunny : Moon" :size="16" />
       </button>
-      <div class="window-controls">
-        <span class="win-btn minimize">—</span>
-        <span class="win-btn maximize">▢</span>
-        <span class="win-btn close">✕</span>
+      <div v-if="desktop" class="window-controls">
+        <button class="win-btn minimize" type="button" :aria-label="t('最小化窗口', 'Minimize window')" @click="minimizeWindow">—</button>
+        <button class="win-btn maximize" type="button" :aria-label="t('最大化或还原窗口', 'Maximize or restore window')" @click="toggleMaximizeWindow">▢</button>
+        <button class="win-btn close" type="button" :aria-label="t('关闭窗口', 'Close window')" @click="requestWindowClose">✕</button>
       </div>
     </div>
-  </div>
+  </header>
 </template>
 
 <style scoped>
@@ -187,6 +199,9 @@ const isDirty = computed(() => editorStore.saveStatus === 'dirty' || editorStore
   color: var(--color-text-secondary);
   border-radius: var(--radius-sm);
   cursor: pointer;
+  padding: 0;
+  border: 0;
+  background: transparent;
   transition: background-color var(--motion-fast), color var(--motion-fast);
 
   &:hover {
diff --git a/frontend/src/features/vault/VaultEntry.vue b/frontend/src/features/vault/VaultEntry.vue
index d84b419..bcb5d15 100644
--- a/frontend/src/features/vault/VaultEntry.vue
+++ b/frontend/src/features/vault/VaultEntry.vue
@@ -122,7 +122,8 @@ async function openFolderPicker() {
 
 <style scoped>
 .vault-entry {
-  height: 100vh;
+  height: 100%;
+  min-height: 0;
   width: 100vw;
   display: flex;
   align-items: center;
diff --git a/frontend/src/services/platform/windowControls.spec.ts b/frontend/src/services/platform/windowControls.spec.ts
new file mode 100644
index 0000000..9271ede
--- /dev/null
+++ b/frontend/src/services/platform/windowControls.spec.ts
@@ -0,0 +1,47 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const native = vi.hoisted(() => ({
+  enabled: false,
+  minimize: vi.fn(),
+  toggleMaximize: vi.fn(),
+  close: vi.fn(),
+}))
+
+vi.mock('@tauri-apps/api/core', () => ({ isTauri: () => native.enabled, invoke: vi.fn() }))
+vi.mock('@tauri-apps/api/window', () => ({
+  getCurrentWindow: () => ({
+    minimize: native.minimize,
+    toggleMaximize: native.toggleMaximize,
+    close: native.close,
+  }),
+}))
+
+import { minimizeWindow, requestWindowClose, toggleMaximizeWindow } from './windowControls'
+
+beforeEach(() => {
+  native.enabled = false
+  native.minimize.mockReset()
+  native.toggleMaximize.mockReset()
+  native.close.mockReset()
+})
+
+describe('桌面窗口控制', () => {
+  it('Web 模式不模拟窗口操作', async () => {
+    await minimizeWindow()
+    await toggleMaximizeWindow()
+    await requestWindowClose()
+    expect(native.minimize).not.toHaveBeenCalled()
+    expect(native.toggleMaximize).not.toHaveBeenCalled()
+    expect(native.close).not.toHaveBeenCalled()
+  })
+
+  it('桌面模式调用当前 Tauri 窗口', async () => {
+    native.enabled = true
+    await minimizeWindow()
+    await toggleMaximizeWindow()
+    await requestWindowClose()
+    expect(native.minimize).toHaveBeenCalledOnce()
+    expect(native.toggleMaximize).toHaveBeenCalledOnce()
+    expect(native.close).toHaveBeenCalledOnce()
+  })
+})
diff --git a/frontend/src/services/platform/windowControls.ts b/frontend/src/services/platform/windowControls.ts
new file mode 100644
index 0000000..ecaabd1
--- /dev/null
+++ b/frontend/src/services/platform/windowControls.ts
@@ -0,0 +1,16 @@
+/** 桌面窗口操作集中于此边界；Web 页面不会显示或模拟原生窗口行为。 */
+import { getCurrentWindow } from '@tauri-apps/api/window'
+import { isDesktop } from './desktop'
+
+export async function minimizeWindow() {
+  if (isDesktop()) await getCurrentWindow().minimize()
+}
+
+export async function toggleMaximizeWindow() {
+  if (isDesktop()) await getCurrentWindow().toggleMaximize()
+}
+
+export async function requestWindowClose() {
+  // close 触发 Rust CloseRequested；Host 会要求前端先保存，再由 lifecycle destroy。
+  if (isDesktop()) await getCurrentWindow().close()
+}