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/server/src/entities/attendance-record.entity.ts

@@ -44,6 +44,9 @@ export class AttendanceRecord {
   @Column({ length: 200, nullable: true })
   remark: string;
 
+  @Column({ name: 'source', length: 20, default: 'manual' })
+  source: string;
+
   @CreateDateColumn({ name: 'created_at' })
   createdAt: Date;