feat: attendance frontend page + backend list/classes endpoints

- Create AttendancePage with filter bar, table, calendar view toggle, batch add modal
- Register /attendance route with PermissionRoute (attendance:view)
- Add menu item in MainLayout with CheckCircleOutlined icon
- Add GET /attendance-records with pagination and filters
- Add GET /attendance-records/classes for class dropdown
- Add source column to AttendanceRecord entity (default: manual)
- Frontend tsc --noEmit: clean; backend: only pre-existing test errors

apps/admin/src/App.tsx

@@ -23,6 +23,7 @@ import ClassroomSchedulePage from './pages/ClassroomSchedule';
 import SchedulesPage from './pages/Schedules';
 import RolesPage from './pages/Roles';
 import PermissionsPage from './pages/Permissions';
+import AttendancePage from './pages/Attendance';
 import PermissionRoute from './components/PermissionRoute';
 
 const PrivateRoute: React.FC<{ children: React.ReactNode }> = ({ children }) => {
@@ -202,6 +203,15 @@ const App: React.FC = () => {
                 }
               />
 
+              <Route
+                path="attendance"
+                element={
+                  <PermissionRoute permission="attendance:view">
+                    <AttendancePage />
+                  </PermissionRoute>
+                }
+              />
+
               <Route
                 path="schedules"
                 element={