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)/admin/attendance/error.tsx

@@ -1,24 +1,7 @@
 "use client"
 
-import { AlertCircle } from "lucide-react"
-import { useTranslations } from "next-intl"
-
-import { EmptyState } from "@/shared/components/ui/empty-state"
+import { RouteErrorBoundary } from "@/shared/components/route-error"
 
 export default function AdminAttendanceError({ reset }: { error: Error & { digest?: string }; reset: () => void }) {
-  const t = useTranslations("attendance")
-  return (
-    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
-      <EmptyState
-        icon={AlertCircle}
-        title={t("errors.unexpected")}
-        description={t("errors.unexpected")}
-        action={{
-          label: t("actions.save"),
-          onClick: () => reset(),
-        }}
-        className="border-none shadow-none h-auto"
-      />
-    </div>
-  )
+  return <RouteErrorBoundary reset={reset} namespace="attendance" />
 }