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/features/create/use-case.ts

@@ -70,7 +70,9 @@ export class CreateAttendeeUseCase {
     const fullName = `${payload.firstName.trim()} ${payload.lastName.trim()}`.trim();
 
     if (group.capacity !== null) {
-      const currentCount = await db.attendee.count({ where: { groupId } });
+      const currentCount = await db.attendee.count({
+        where: { groupId, status: 'ACTIVE' },
+      });
 
       if (currentCount >= group.capacity) {
         if (isOwner && !options.allowOverflow) {