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)/teacher/classes/my/[id]/error.tsx

@@ -0,0 +1,13 @@
+"use client"
+
+import { ErrorState } from "@/shared/components/error-state"
+
+export default function ClassDetailError({
+  error,
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return <ErrorState error={error} reset={reset} namespace="classes" />
+}

src/app/(dashboard)/teacher/classes/my/[id]/loading.tsx

@@ -0,0 +1,41 @@
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="flex h-full flex-col space-y-8 p-8">
+      <div className="space-y-2">
+        <Skeleton className="h-7 w-48" />
+        <Skeleton className="h-4 w-64" />
+      </div>
+      <div className="grid gap-6 lg:grid-cols-3">
+        <div className="lg:col-span-2 space-y-6">
+          <div className="rounded-lg border bg-card p-6 space-y-4">
+            <Skeleton className="h-5 w-32" />
+            <div className="grid grid-cols-2 gap-4">
+              {Array.from({ length: 4 }).map((_, i) => (
+                <div key={i} className="space-y-2">
+                  <Skeleton className="h-4 w-20" />
+                  <Skeleton className="h-8 w-full" />
+                </div>
+              ))}
+            </div>
+          </div>
+          <div className="rounded-lg border bg-card p-6 space-y-3">
+            <Skeleton className="h-5 w-24" />
+            {Array.from({ length: 5 }).map((_, i) => (
+              <Skeleton key={i} className="h-12 w-full" />
+            ))}
+          </div>
+        </div>
+        <div className="space-y-6">
+          <div className="rounded-lg border bg-card p-6 space-y-3">
+            <Skeleton className="h-5 w-28" />
+            {Array.from({ length: 3 }).map((_, i) => (
+              <Skeleton key={i} className="h-16 w-full" />
+            ))}
+          </div>
+        </div>
+      </div>
+    </div>
+  )
+}

src/app/(dashboard)/teacher/classes/my/[id]/page.tsx

@@ -1,10 +1,13 @@
+import type { Metadata } from "next"
 import type { JSX } from "react"
 import { notFound } from "next/navigation"
+import { getTranslations } from "next-intl/server"
 
 import { requirePermission } from "@/shared/lib/auth-guard"
 import { Permissions } from "@/shared/types/permissions"
 import { getClassHomeworkInsights, getClassSchedule, getClassStudentSubjectScoresV2, getClassStudents } from "@/modules/classes/data-access"
 import { ClassAssignmentsWidget } from "@/modules/classes/components/class-detail/class-assignments-widget"
+import { ClassErrorBoundary } from "@/modules/classes/components/class-error-boundary"
 import { ClassTrendsWidget } from "@/modules/classes/components/class-detail/class-trends-widget"
 import { ClassHeader } from "@/modules/classes/components/class-detail/class-header"
 import { ClassOverviewStats } from "@/modules/classes/components/class-detail/class-overview-stats"
@@ -13,6 +16,14 @@ import { ClassStudentsWidget } from "@/modules/classes/components/class-detail/c
 
 export const dynamic = "force-dynamic"
 
+export async function generateMetadata(): Promise<Metadata> {
+  const t = await getTranslations("classes")
+  return {
+    title: `${t("metadata.classDetail")} - Next_Edu`,
+    description: t("metadata.classDetail"),
+  }
+}
+
 export default async function ClassDetailPage({
   params,
 }: {
@@ -66,45 +77,47 @@ export default async function ClassDetailPage({
 
   return (
     <div className="flex min-h-screen flex-col bg-muted/10">
-      <ClassHeader
-        classId={insights.class.id}
-        name={insights.class.name}
-        grade={insights.class.grade}
-        homeroom={insights.class.homeroom}
-        room={insights.class.room}
-        schoolName={insights.class.schoolName}
-        studentCount={insights.studentCounts.total}
-      />
-
-      <div className="flex-1 space-y-6 p-6">
-        {/* Key Metrics */}
-        <ClassOverviewStats
-          averageScore={insights.overallScores.avg}
-          submissionRate={totalSubmissionRate * 100}
-          papersToGrade={papersToGrade}
-          overdueCount={overdueCount}
+      <ClassErrorBoundary>
+        <ClassHeader
+          classId={insights.class.id}
+          name={insights.class.name}
+          grade={insights.class.grade}
+          homeroom={insights.class.homeroom}
+          room={insights.class.room}
+          schoolName={insights.class.schoolName}
+          studentCount={insights.studentCounts.total}
         />
 
-        <div className="grid grid-cols-1 gap-6 lg:grid-cols-3">
-          {/* Main Content Area (Left 2/3) */}
-          <div className="min-w-0 space-y-6 lg:col-span-2">
-            <ClassTrendsWidget assignments={assignmentSummaries} />
-            <ClassStudentsWidget
-              classId={insights.class.id}
-              students={studentSummaries}
-            />
-          </div>
+        <div className="flex-1 space-y-6 p-6">
+          {/* Key Metrics */}
+          <ClassOverviewStats
+            averageScore={insights.overallScores.avg}
+            submissionRate={totalSubmissionRate * 100}
+            papersToGrade={papersToGrade}
+            overdueCount={overdueCount}
+          />
 
-          {/* Sidebar Area (Right 1/3) */}
-          <div className="min-w-0 space-y-6">
-            <ClassScheduleWidget classId={insights.class.id} schedule={schedule} />
-            <ClassAssignmentsWidget
-              classId={insights.class.id}
-              assignments={assignmentSummaries}
-            />
+          <div className="grid grid-cols-1 gap-6 lg:grid-cols-3">
+            {/* Main Content Area (Left 2/3) */}
+            <div className="min-w-0 space-y-6 lg:col-span-2">
+              <ClassTrendsWidget assignments={assignmentSummaries} />
+              <ClassStudentsWidget
+                classId={insights.class.id}
+                students={studentSummaries}
+              />
+            </div>
+
+            {/* Sidebar Area (Right 1/3) */}
+            <div className="min-w-0 space-y-6">
+              <ClassScheduleWidget classId={insights.class.id} schedule={schedule} />
+              <ClassAssignmentsWidget
+                classId={insights.class.id}
+                assignments={assignmentSummaries}
+              />
+            </div>
           </div>
         </div>
-      </div>
+      </ClassErrorBoundary>
     </div>
   )
 }

src/app/(dashboard)/teacher/classes/my/error.tsx

@@ -0,0 +1,13 @@
+"use client"
+
+import { ErrorState } from "@/shared/components/error-state"
+
+export default function MyClassesError({
+  error,
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return <ErrorState error={error} reset={reset} namespace="classes" />
+}

src/app/(dashboard)/teacher/classes/my/page.tsx

@@ -1,18 +1,31 @@
+import type { Metadata } from "next"
 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 { getClassSubjects, getTeacherClasses } from "@/modules/classes/data-access"
+import { ClassErrorBoundary } from "@/modules/classes/components/class-error-boundary"
 import { MyClassesGrid } from "@/modules/classes/components/my-classes-grid"
 
 export const dynamic = "force-dynamic"
 
+export async function generateMetadata(): Promise<Metadata> {
+  const t = await getTranslations("classes")
+  return {
+    title: `${t("metadata.myClasses")} - Next_Edu`,
+    description: t("metadata.myClasses"),
+  }
+}
+
 export default async function MyClassesPage(): Promise<JSX.Element> {
   await requirePermission(Permissions.CLASS_READ)
   const [classes, subjectOptions] = await Promise.all([getTeacherClasses(), getClassSubjects()])
 
   return (
     <div className="flex h-full flex-col space-y-4 p-8">
-      <MyClassesGrid classes={classes} subjectOptions={subjectOptions} />
+      <ClassErrorBoundary>
+        <MyClassesGrid classes={classes} subjectOptions={subjectOptions} />
+      </ClassErrorBoundary>
     </div>
   )
 }

src/app/(dashboard)/teacher/classes/schedule/error.tsx

@@ -0,0 +1,13 @@
+"use client"
+
+import { ErrorState } from "@/shared/components/error-state"
+
+export default function ScheduleError({
+  error,
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return <ErrorState error={error} reset={reset} namespace="classes" />
+}

src/app/(dashboard)/teacher/classes/schedule/page.tsx

@@ -1,21 +1,33 @@
+import type { Metadata } from "next"
 import type { JSX } from "react"
 import { Suspense } from "react"
 import { Calendar } from "lucide-react"
+import { getTranslations } from "next-intl/server"
 
 import { requirePermission } from "@/shared/lib/auth-guard"
 import { Permissions } from "@/shared/types/permissions"
 import { getClassSchedule, getTeacherClasses } from "@/modules/classes/data-access"
 import { ScheduleFilters } from "@/modules/classes/components/schedule-filters"
 import { ScheduleView } from "@/modules/classes/components/schedule-view"
+import { ClassErrorBoundary } from "@/modules/classes/components/class-error-boundary"
 import { EmptyState } from "@/shared/components/ui/empty-state"
 import { Skeleton } from "@/shared/components/ui/skeleton"
 import { getParam, type SearchParams } from "@/shared/lib/search-params"
 
 export const dynamic = "force-dynamic"
 
+export async function generateMetadata(): Promise<Metadata> {
+  const t = await getTranslations("classes")
+  return {
+    title: `${t("metadata.schedule")} - Next_Edu`,
+    description: t("metadata.schedule"),
+  }
+}
+
 async function ScheduleResults({ searchParams }: { searchParams: Promise<SearchParams> }): Promise<JSX.Element> {
   const params = await searchParams
   const classId = getParam(params, "classId")
+  const t = await getTranslations("classes")
 
   const classes = await getTeacherClasses()
   const schedule = await getClassSchedule({
@@ -28,9 +40,9 @@ async function ScheduleResults({ searchParams }: { searchParams: Promise<SearchP
     return (
       <EmptyState
         icon={Calendar}
-        title={hasFilters ? "No schedule for this class" : "No schedule available"}
-        description={hasFilters ? "Try selecting another class." : "Your class schedule has not been set up yet."}
-        action={hasFilters ? { label: "Clear filters", href: "/teacher/classes/schedule" } : undefined}
+        title={hasFilters ? t("schedule.empty.noMatch") : t("schedule.empty.title")}
+        description={hasFilters ? t("schedule.empty.noMatchDescription") : t("schedule.empty.description")}
+        action={hasFilters ? { label: t("filters.reset"), href: "/teacher/classes/schedule" } : undefined}
         className="h-[360px] bg-card"
       />
     )
@@ -66,13 +78,15 @@ export default async function SchedulePage({ searchParams }: { searchParams: Pro
   return (
     <div className="flex h-full flex-col space-y-8 p-8">
       <div className="space-y-6">
-        <Suspense fallback={<div className="h-10 w-full animate-pulse rounded-md bg-muted" />}>
-          <ScheduleFilters classes={classes} />
-        </Suspense>
+        <ClassErrorBoundary>
+          <Suspense fallback={<div className="h-10 w-full animate-pulse rounded-md bg-muted" />}>
+            <ScheduleFilters classes={classes} />
+          </Suspense>
 
-        <Suspense fallback={<ScheduleResultsFallback />}>
-          <ScheduleResults searchParams={searchParams} />
-        </Suspense>
+          <Suspense fallback={<ScheduleResultsFallback />}>
+            <ScheduleResults searchParams={searchParams} />
+          </Suspense>
+        </ClassErrorBoundary>
       </div>
     </div>
   )

src/app/(dashboard)/teacher/classes/students/error.tsx

@@ -0,0 +1,13 @@
+"use client"
+
+import { ErrorState } from "@/shared/components/error-state"
+
+export default function StudentsError({
+  error,
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return <ErrorState error={error} reset={reset} namespace="classes" />
+}

src/app/(dashboard)/teacher/classes/students/page.tsx

@@ -1,20 +1,32 @@
+import type { Metadata } from "next"
 import type { JSX } from "react"
 import { Suspense } from "react"
 import { User } from "lucide-react"
+import { getTranslations } from "next-intl/server"
 
 import { requirePermission } from "@/shared/lib/auth-guard"
 import { Permissions } from "@/shared/types/permissions"
 import { getClassStudents, getTeacherClasses, getStudentsSubjectScores } from "@/modules/classes/data-access"
 import { StudentsFilters } from "@/modules/classes/components/students-filters"
 import { StudentsTable } from "@/modules/classes/components/students-table"
+import { ClassErrorBoundary } from "@/modules/classes/components/class-error-boundary"
 import { EmptyState } from "@/shared/components/ui/empty-state"
 import { Skeleton } from "@/shared/components/ui/skeleton"
 import { getParam, type SearchParams } from "@/shared/lib/search-params"
 
 export const dynamic = "force-dynamic"
 
+export async function generateMetadata(): Promise<Metadata> {
+  const t = await getTranslations("classes")
+  return {
+    title: `${t("metadata.students")} - Next_Edu`,
+    description: t("metadata.students"),
+  }
+}
+
 async function StudentsResults({ searchParams, defaultClassId }: { searchParams: Promise<SearchParams>, defaultClassId?: string }): Promise<JSX.Element> {
   const params = await searchParams
+  const t = await getTranslations("classes")
 
   const q = getParam(params, "q") || undefined
   const classId = getParam(params, "classId")
@@ -25,7 +37,7 @@ async function StudentsResults({ searchParams, defaultClassId }: { searchParams:
   // However, the requirement is "Default to showing the first class".
   // If classId param is missing, we use defaultClassId.
   const targetClassId = classId ? (classId !== "all" ? classId : undefined) : defaultClassId
-  
+
   const filteredStudents = await getClassStudents({
     q,
     classId: targetClassId,
@@ -47,9 +59,9 @@ async function StudentsResults({ searchParams, defaultClassId }: { searchParams:
     return (
       <EmptyState
         icon={User}
-        title={hasFilters ? "No students match your filters" : "No students found"}
-        description={hasFilters ? "Try clearing filters or adjusting keywords." : "There are no students in your classes yet."}
-        action={hasFilters ? { label: "Clear filters", href: "/teacher/classes/students" } : undefined}
+        title={hasFilters ? t("students.empty.noMatch") : t("students.empty.title")}
+        description={hasFilters ? t("students.empty.noMatchDescription") : t("students.empty.description")}
+        action={hasFilters ? { label: t("filters.reset"), href: "/teacher/classes/students" } : undefined}
         className="h-[360px] bg-card"
       />
     )
@@ -80,20 +92,22 @@ function StudentsResultsFallback() {
 export default async function StudentsPage({ searchParams }: { searchParams: Promise<SearchParams> }): Promise<JSX.Element> {
   await requirePermission(Permissions.CLASS_READ)
   const classes = await getTeacherClasses()
-  
+
   // Logic to determine default class (first one available)
   const defaultClassId = classes.length > 0 ? classes[0].id : undefined
 
   return (
     <div className="flex h-full flex-col space-y-4 p-8">
       <div className="space-y-4">
-        <Suspense fallback={<div className="h-10 w-full animate-pulse rounded-md bg-muted" />}>
-          <StudentsFilters classes={classes} defaultClassId={defaultClassId} />
-        </Suspense>
+        <ClassErrorBoundary>
+          <Suspense fallback={<div className="h-10 w-full animate-pulse rounded-md bg-muted" />}>
+            <StudentsFilters classes={classes} defaultClassId={defaultClassId} />
+          </Suspense>
 
-        <Suspense fallback={<StudentsResultsFallback />}>
-          <StudentsResults searchParams={searchParams} defaultClassId={defaultClassId} />
-        </Suspense>
+          <Suspense fallback={<StudentsResultsFallback />}>
+            <StudentsResults searchParams={searchParams} defaultClassId={defaultClassId} />
+          </Suspense>
+        </ClassErrorBoundary>
       </div>
     </div>
   )