feat(app): add error/loading boundaries across all dashboard routes and new routes

- Add error.tsx and loading.tsx boundaries for admin, parent, student, teacher routes

- Add admin announcements edit, audit-logs overview, curriculum-map, invitation-codes, permissions, questions, roles routes

- Add admin elective detail and components, files, course-plans, users, scheduling boundaries

- Add messages group-compose route

- Add parent course-plans, elective, grades report-card, practice routes

- Add student course-plans, elective detail, error-book dialogs, grades report-card, learning study-path, leave, schedule boundaries

- Add teacher attendance report, classes boundaries, course-plans boundaries, elective, exams analytics/edit-rich/all/create/new, grades report-card, homework boundaries, leave, lesson-plans calendar

- Add auth loading, onboarding loading, api cron

src/app/(dashboard)/messages/page.tsx

@@ -1,10 +1,16 @@
+import { Suspense } from "react"
+import type { JSX } from "react"
 import { getTranslations } from "next-intl/server"
 
 import { requirePermission } from "@/shared/lib/auth-guard"
 import { Permissions } from "@/shared/types/permissions"
-import { getMessagesPageData } from "@/modules/messaging/data-access"
-import { MessageList } from "@/modules/messaging/components/message-list"
+import { SectionErrorBoundary } from "@/shared/components/section-error-boundary"
+import { getNotifications } from "@/modules/notifications/data-access"
 import { NotificationList } from "@/modules/notifications/components/notification-list"
+import { MessageListSection } from "@/modules/messaging/components/message-list-section"
+import { MessageListSkeleton } from "@/modules/messaging/components/message-list-skeleton"
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
 
 export const dynamic = "force-dynamic"
 
@@ -13,13 +19,40 @@ export async function generateMetadata() {
   return { title: t("title.list") }
 }
 
-export default async function MessagesPage() {
+/**
+ * P2-9: 通知列表区块骨架屏（Suspense fallback）。
+ */
+function NotificationListSkeleton(): JSX.Element {
+  return (
+    <div className="space-y-4" role="status" aria-label="Loading notifications">
+      <Skeleton className="h-10 w-48" />
+      {Array.from({ length: 3 }).map((_, i) => (
+        <Card key={i} aria-hidden="true">
+          <CardHeader className="space-y-2 pb-3">
+            <Skeleton className="h-4 w-3/4" />
+            <Skeleton className="h-3 w-1/2" />
+          </CardHeader>
+          <CardContent className="pt-0">
+            <Skeleton className="h-3 w-full" />
+          </CardContent>
+        </Card>
+      ))}
+    </div>
+  )
+}
+
+/**
+ * P2-9: 通知列表区块（Server Component，流式加载）。
+ */
+async function NotificationListSection({ userId }: { userId: string }): Promise<JSX.Element> {
+  const result = await getNotifications(userId, { page: 1, pageSize: 20 })
+  return <NotificationList notifications={result.items} />
+}
+
+export default async function MessagesPage(): Promise<JSX.Element> {
   const t = await getTranslations("messages")
   const ctx = await requirePermission(Permissions.MESSAGE_READ)
 
-  const { messages: messagesResult, notifications: notificationsResult } =
-    await getMessagesPageData(ctx.userId)
-
   return (
     <div className="flex h-full flex-col space-y-8 p-8">
       <div>
@@ -29,9 +62,19 @@ export default async function MessagesPage() {
         </p>
       </div>
 
-      <MessageList messages={messagesResult.items} currentUserId={ctx.userId} />
+      {/* P2-8 + P2-9: 消息列表区块独立 Suspense + ErrorBoundary，局部失败不影响通知区块 */}
+      <Suspense fallback={<MessageListSkeleton />}>
+        <SectionErrorBoundary namespace="messages">
+          <MessageListSection userId={ctx.userId} canGroupSend={ctx.dataScope.type === "class_taught"} />
+        </SectionErrorBoundary>
+      </Suspense>
 
-      <NotificationList notifications={notificationsResult.items} />
+      {/* P2-8 + P2-9: 通知列表区块独立 Suspense + ErrorBoundary */}
+      <Suspense fallback={<NotificationListSkeleton />}>
+        <SectionErrorBoundary namespace="notifications">
+          <NotificationListSection userId={ctx.userId} />
+        </SectionErrorBoundary>
+      </Suspense>
     </div>
   )
 }