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/attendance/sheet/error.tsx

@@ -0,0 +1,7 @@
+"use client"
+
+import { RouteErrorBoundary } from "@/shared/components/route-error"
+
+export default function AttendanceSheetError({ reset }: { error: Error & { digest?: string }; reset: () => void }) {
+  return <RouteErrorBoundary reset={reset} namespace="attendance" />
+}

src/app/(dashboard)/teacher/attendance/sheet/page.tsx

@@ -1,5 +1,7 @@
 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 { getTeacherClasses } from "@/modules/classes/data-access"
 import { getClassStudentsForAttendance } from "@/modules/attendance/data-access"
 import { AttendanceSheet } from "@/modules/attendance/components/attendance-sheet"
@@ -12,6 +14,7 @@ export default async function AttendanceSheetPage({
 }: {
   searchParams: Promise<SearchParams>
 }): Promise<JSX.Element> {
+  await requirePermission(Permissions.ATTENDANCE_MANAGE)
   const t = await getTranslations("attendance")
   const sp = await searchParams