feat: add absence notification and analytics features

- Implemented AbsenceNotifyView for notifying absence with session details.
- Created AnalyticsView for displaying group analytics and managing students at risk.
- Added ClassAttendanceView for marking attendance in classes.
- Defined new schemas for analytics and attendance in shared package.

apps/backend/src/modules/attendees/lib/helpers.ts

@@ -9,6 +9,7 @@ export type AttendeeRecord = {
   guardianName: string | null;
   guardianPhone: string | null;
   notes: string | null;
+  notifyToken?: string | null;
   createdAt: Date;
   updatedAt: Date;
 };
@@ -23,6 +24,7 @@ export function toAttendeeDto(record: AttendeeRecord): AttendeeDto {
     guardianName: record.guardianName,
     guardianPhone: record.guardianPhone,
     notes: record.notes,
+    notifyToken: record.notifyToken ?? null,
     createdAt: record.createdAt.toISOString(),
     updatedAt: record.updatedAt.toISOString(),
   };