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/student-dashboard/student-today-schedule-card.tsx

@@ -10,6 +10,7 @@ import { Badge } from "@/shared/components/ui/badge"
 import { ScheduleList } from "@/shared/components/schedule/schedule-list"
 import { Card, CardContent, CardHeader, CardTitle } from "@/shared/components/ui/card"
 import { EmptyState } from "@/shared/components/ui/empty-state"
+import { useCurrentTime } from "@/shared/hooks"
 import { cn } from "@/shared/lib/utils"
 import type { StudentTodayScheduleItem } from "@/modules/dashboard/types"
 
@@ -21,9 +22,9 @@ const timeToMinutes = (t: string): number => {
 export function StudentTodayScheduleCard({ items }: { items: StudentTodayScheduleItem[] }) {
   const t = useTranslations("dashboard")
   const hasSchedule = items.length > 0
+  const now = useCurrentTime()
 
   const { currentId, nextId } = useMemo(() => {
-    const now = new Date()
     const nowMin = now.getHours() * 60 + now.getMinutes()
     let currentId: string | null = null
     let nextId: string | null = null
@@ -40,7 +41,7 @@ export function StudentTodayScheduleCard({ items }: { items: StudentTodaySchedul
       }
     }
     return { currentId, nextId }
-  }, [items])
+  }, [items, now])
 
   return (
     <Card>
@@ -59,6 +60,7 @@ export function StudentTodayScheduleCard({ items }: { items: StudentTodaySchedul
             icon={CalendarX}
             title={t("empty.noClassesToday")}
             description={t("empty.noClassesTodayDesc")}
+            action={{ label: t("quickActions.viewSchedule"), href: "/student/schedule" }}
             className="border-none h-72"
           />
         ) : (