feat(dashboard): 实现所有长期问题修复（P2-1/P2-5/P2-7/P2-9）

P2-9: TeacherSchedule 重复渲染优化
- 将移动端（lg:hidden）和桌面端（hidden lg:block）的双实例渲染改为单实例
- 使用 CSS flex order + grid col-start/row-start 实现响应式布局重排序
- 消除服务端 HTML 负载翻倍问题

P2-5: StudentTodayScheduleCard 时间过时修复
- 新增 useCurrentTime hook（src/shared/hooks/use-current-time.ts）
- 每分钟自动更新当前时间，useMemo 依赖 [items, now] 确保徽章不过时
- SSR 安全：初始渲染用 new Date()，挂载后 setInterval 更新

P2-1: 流式/Suspense 架构改造
- 新增 getAdminDashboardStreams（streams.ts）：返回各独立数据源的未解析 Promise
- Admin dashboard：7 个分区组件用 React use() 独立消费 Promise，各 Suspense 边界独立流式渲染
- Teacher/Student/Parent dashboard：传入未解析 Promise，视图用 use() 消费，启用 Suspense 流式
- 页面外壳（标题 + 快捷操作）立即渲染，数据到达后各分区按各自速度填充

P2-7: 组件测试 + 路由测试修复
- 修复 dashboard-routing.test.ts：移除误导性的 permissions 字段（实际用 resolvePermissions(roles)）
- 新增 fallback 路由测试（未知角色 → teacher dashboard）
- 新增 DashboardSection 组件测试（6 个测试：骨架屏变体 + 错误边界 + 正常渲染）
- 新增 useCurrentTime hook 测试（3 个测试：初始值 + 间隔更新 + 清理）

同步更新:
- docs/architecture/005_architecture_data.json 新增 7 个流式组件 + useCurrentTime hook + getAdminDashboardStreams 条目

tests/integration/dashboard-routing.test.ts

@@ -17,6 +17,13 @@ vi.mock("next/navigation", () => ({
 
 import DashboardPage from "@/app/(dashboard)/dashboard/page"
 
+/**
+ * 仪表盘路由分发测试
+ *
+ * 注意：实际代码用 `resolvePermissions(roles)` 从角色推导权限，
+ * 而非读取 user.permissions 字段。因此 mock 中只需设置 roles，
+ * 无需（也不应）设置 permissions 字段，以免误导。
+ */
 describe("dashboard route dispatcher", () => {
   beforeEach(() => {
     vi.resetAllMocks()
@@ -35,30 +42,37 @@ describe("dashboard route dispatcher", () => {
     await expect(DashboardPage()).rejects.toThrow("REDIRECT:/login")
   })
 
-  it("redirects admin (school:manage) to admin dashboard", async () => {
+  it("redirects admin to admin dashboard", async () => {
     mocks.authMock.mockResolvedValue({
-      user: { id: "u_admin", roles: ["admin"], permissions: ["school:manage"] },
+      user: { id: "u_admin", roles: ["admin"] },
     })
     await expect(DashboardPage()).rejects.toThrow("REDIRECT:/admin/dashboard")
   })
 
-  it("redirects student (homework:submit without exam:create) to student dashboard", async () => {
+  it("redirects student to student dashboard", async () => {
     mocks.authMock.mockResolvedValue({
-      user: { id: "u_student", roles: ["student"], permissions: ["homework:submit"] },
+      user: { id: "u_student", roles: ["student"] },
     })
     await expect(DashboardPage()).rejects.toThrow("REDIRECT:/student/dashboard")
   })
 
   it("redirects parent to parent dashboard", async () => {
     mocks.authMock.mockResolvedValue({
-      user: { id: "u_parent", roles: ["parent"], permissions: ["exam:read"] },
+      user: { id: "u_parent", roles: ["parent"] },
     })
     await expect(DashboardPage()).rejects.toThrow("REDIRECT:/parent/dashboard")
   })
 
-  it("redirects teacher (with exam:create) to teacher dashboard", async () => {
+  it("redirects teacher to teacher dashboard", async () => {
     mocks.authMock.mockResolvedValue({
-      user: { id: "u_teacher", roles: ["teacher"], permissions: ["exam:create", "exam:read"] },
+      user: { id: "u_teacher", roles: ["teacher"] },
+    })
+    await expect(DashboardPage()).rejects.toThrow("REDIRECT:/teacher/dashboard")
+  })
+
+  it("redirects unknown role to teacher dashboard (fallback)", async () => {
+    mocks.authMock.mockResolvedValue({
+      user: { id: "u_unknown", roles: [] },
     })
     await expect(DashboardPage()).rejects.toThrow("REDIRECT:/teacher/dashboard")
   })