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

src/modules/dashboard/components/teacher-dashboard/teacher-dashboard-view.tsx

@@ -1,5 +1,7 @@
+import { use } from "react"
 import type { TeacherDashboardData } from "@/modules/dashboard/types"
 import type { TeacherDashboardMetrics } from "@/modules/dashboard/lib/dashboard-utils"
+import type { ActionState } from "@/shared/types/action-state"
 import { getTranslations } from "next-intl/server"
 import type { TeacherTodoItem } from "./teacher-todo-card"
 
@@ -13,11 +15,24 @@ import { TeacherStats } from "./teacher-stats"
 import { TeacherGradeTrends } from "./teacher-grade-trends"
 import { TeacherTodoCard } from "./teacher-todo-card"
 
-interface TeacherDashboardViewProps {
-  data: TeacherDashboardData & { metrics: TeacherDashboardMetrics }
+type TeacherDashboardResult = ActionState<TeacherDashboardData & { metrics: TeacherDashboardMetrics }>
+
+/**
+ * 教师仪表盘视图（P2-1 流式架构）
+ *
+ * 接收未解析的 Promise，用 React `use()` 消费。
+ * 页面外壳立即渲染，数据到达后在 DashboardSection 的 Suspense 边界内填充。
+ */
+export function TeacherDashboardView({ dataPromise }: { dataPromise: Promise<TeacherDashboardResult> }) {
+  const result = use(dataPromise)
+  if (!result.success || !result.data) {
+    throw new Error(result.message ?? "Failed to load teacher dashboard")
+  }
+
+  return <TeacherDashboardContent data={result.data} />
 }
 
-export async function TeacherDashboardView({ data }: TeacherDashboardViewProps) {
+async function TeacherDashboardContent({ data }: { data: TeacherDashboardData & { metrics: TeacherDashboardMetrics } }) {
   const t = await getTranslations("dashboard")
   const { metrics } = data
 
@@ -58,13 +73,15 @@ export async function TeacherDashboardView({ data }: TeacherDashboardViewProps)
         />
       </DashboardSection>
 
-      <div className="grid gap-6 lg:grid-cols-12">
-        <section aria-label={t("sections.pendingGrading")} className="flex flex-col gap-6 lg:col-span-8">
-          <div className="lg:hidden">
-            <DashboardSection variant="card">
-              <TeacherSchedule items={metrics.todayScheduleItems} />
-            </DashboardSection>
-          </div>
+      <div className="flex flex-col gap-6 lg:grid lg:grid-cols-12">
+        {/* 课表：移动端首位，桌面端右上 — 仅渲染一次（P2-9 修复，原为双实例） */}
+        <div className="order-1 lg:col-start-9 lg:col-span-4 lg:row-start-1">
+          <DashboardSection variant="card">
+            <TeacherSchedule items={metrics.todayScheduleItems} />
+          </DashboardSection>
+        </div>
+
+        <section aria-label={t("sections.pendingGrading")} className="flex flex-col gap-6 order-2 lg:col-start-1 lg:col-span-8 lg:row-start-1 lg:row-span-2">
           <DashboardSection variant="card">
             <TeacherTodoCard items={todoItems} />
           </DashboardSection>
@@ -81,12 +98,7 @@ export async function TeacherDashboardView({ data }: TeacherDashboardViewProps)
           </DashboardSection>
         </section>
 
-        <aside aria-label={t("sections.myClasses")} className="flex flex-col gap-6 lg:col-span-4">
-          <div className="hidden lg:block">
-            <DashboardSection variant="card">
-              <TeacherSchedule items={metrics.todayScheduleItems} />
-            </DashboardSection>
-          </div>
+        <aside aria-label={t("sections.myClasses")} className="flex flex-col gap-6 order-3 lg:col-start-9 lg:col-span-4 lg:row-start-2">
           <DashboardSection variant="list">
             <TeacherHomeworkCard assignments={data.assignments} />
           </DashboardSection>