feat(collaboration): 完善在线文档协作与通知闭环

- 新增协作文件夹、文件、不可变修订、成员、会话、回调回执、编辑申请与分享链接数据模型。

- 补齐新建、导入、复制、下载、回收站、恢复、成员授权、所有权转让及文件级权限接口。

- 接入 ONLYOFFICE 共同编辑、历史版本预览与恢复、修订另存副本、导出下载审计和幂等回调保存。

- 增加编辑权限申请、审批通知、项目提醒聚合、通知 Feed、已读处理及历史待办数据回填。

- 支持公开分享的查看或编辑模式、有效期、密码哈希、失败锁定、短时访问凭证与固定分享地址。

- 增加协作者导出、申请编辑、工作表结构保护和所有权管理策略，并纳入项目接口权限矩阵。

- 新增协作文件库、编辑工作区、公开分享页、下载与另存为对话框，以及导航、路由和权限入口。

- 统一网页端与桌面端通知布局，增加沉浸式工作区和浏览器、Tauri 双端全屏能力。

- 扩展运行时文件下载适配、Tauri 环境识别和原生全屏命令，继续保持业务代码运行时边界。

- 加固 ONLYOFFICE 消息桥的同源下载、签名地址隔离和保存为能力校验，并更新桌面发布检查。

- 增加连续数据库迁移、50MB 上传限制、OnlyOffice 中文文案与开发启动路由校验。

- 补充协作、通知、权限、路由、运行时、布局和 OnlyOffice 相关测试及模块说明文档。

frontend/src/components/Layout.desktop.test.ts

@@ -76,7 +76,8 @@ describe("desktop layout shell", () => {
   it("keeps web project switching routed through the workbench entry", () => {
     const webLayout = readWebLayoutSource();
 
-    expect(webLayout).toContain('v-if="hasProjectContext" class="workbench-return-button"');
+    expect(webLayout).not.toContain("workbench-return-button");
+    expect(webLayout).toContain('<el-dropdown-item command="workbench">');
     expect(webLayout).toContain('await router.push("/workbench")');
     expect(webLayout).toContain("const hasProjectContext = computed(() => Boolean(study.currentStudy) && !isAdminContext.value);");
     expect(webLayout).toContain('v-if="hasProjectContext && hasAnyProjectModuleAccess"');
@@ -218,6 +219,18 @@ describe("desktop layout shell", () => {
     expect(layout).toContain("pointer-events: none;");
   });
 
+  it("uses the collaboration route immersive mode in the desktop shell", () => {
+    const layout = readDesktopLayoutSource();
+
+    expect(layout).toContain("'is-immersive-workspace': route.meta.immersiveWorkspace");
+    expect(layout).toContain('<aside v-if="!route.meta.immersiveWorkspace" class="desktop-sidebar">');
+    expect(layout).toContain('<header v-if="!route.meta.immersiveWorkspace" class="desktop-toolbar">');
+    expect(layout).toContain('v-if="!route.meta.immersiveWorkspace && workspaceTabs.length > 1"');
+    expect(layout).toContain(".desktop-workbench.is-immersive-workspace {");
+    expect(layout).toContain(".desktop-workbench.is-immersive-workspace .desktop-main {");
+    expect(layout).toContain(".desktop-workbench.is-immersive-workspace .desktop-content {");
+  });
+
   it("renders desktop preferences as a split settings panel", () => {
     const preferences = readDesktopPreferencesSource();
     const desktopLayout = readDesktopLayoutSource();
@@ -302,7 +315,9 @@ describe("desktop layout shell", () => {
 
   it("keeps workspace tabs stable and draggable like browser tabs", () => {
     const source = readDesktopLayoutSource();
-    const tabsStart = source.indexOf('<div v-if="workspaceTabs.length > 1" class="workspace-tabs">');
+    const tabsStart = source.indexOf(
+      '<div v-if="!route.meta.immersiveWorkspace && workspaceTabs.length > 1" class="workspace-tabs">',
+    );
     const tabsEnd = source.indexOf('<main class="desktop-content"', tabsStart);
     const tabsTemplate = source.slice(tabsStart, tabsEnd);
 
@@ -378,6 +393,7 @@ describe("desktop layout shell", () => {
     const source = readDesktopLayoutSource();
 
     expect(source).toContain("const workspaceTaskOrigins = ref<Record<string, string>>({});");
+    expect(source).toContain('group: String(route.meta.workspaceTaskGroup || "工作区任务")');
     expect(source).toContain("if (route.meta.transientWorkspaceTask && previousTabPath && previousTabPath !== current.path)");
     expect(source).toContain("workspaceTabs.value.find((tab) => tab.path === originPath)");
     expect(source).toContain("provide(workspaceTaskControllerKey, { closeTransientTask: closeTransientWorkspaceTask });");
@@ -406,7 +422,9 @@ describe("desktop layout shell", () => {
 
   it("shows the four most recently opened tasks with a searchable all-tasks menu after five tabs", () => {
     const source = readDesktopLayoutSource();
-    const tabsStart = source.indexOf('<div v-if="workspaceTabs.length > 1" class="workspace-tabs">');
+    const tabsStart = source.indexOf(
+      '<div v-if="!route.meta.immersiveWorkspace && workspaceTabs.length > 1" class="workspace-tabs">',
+    );
     const tabsEnd = source.indexOf('<main class="desktop-content"', tabsStart);
     const tabsTemplate = source.slice(tabsStart, tabsEnd);
 
@@ -590,6 +608,9 @@ describe("desktop layout shell", () => {
   it("keeps routed desktop pages stretched to the content boundary", () => {
     const layout = readDesktopLayoutSource();
 
+    expect(layout).toContain(".desktop-toolbar {\n  grid-row: 1;");
+    expect(layout).toContain(".workspace-tabs {\n  grid-row: 2;");
+    expect(layout).toContain(".desktop-content {\n  grid-row: 3;");
     expect(layout).toContain(".desktop-route-shell {");
     expect(layout).toContain("width: 100%;");
     expect(layout).toContain("max-width: 100%;");