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/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>
   )