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/classes/features/notify-absence/route.ts

@@ -0,0 +1,24 @@
+import type { NotifyAbsence } from '@gruperly/shared';
+import { NotifyAbsenceSchema } from '@gruperly/shared';
+import { Hono } from 'hono';
+import { problemJson, resultJson, unauthorizedProblem } from '@/http/problem-details';
+import { validate } from '@/http/validate';
+import { NotifySessionAbsence } from './use-case';
+
+const route = new Hono();
+
+route.post('/:sessionId/notify-absence', validate.json(NotifyAbsenceSchema), async (c) => {
+  const user = c.get('user');
+  if (!user) {
+    return problemJson(c, unauthorizedProblem(c.req.path));
+  }
+
+  const sessionId = c.req.param('sessionId');
+  const payload = c.req.valid('json') as NotifyAbsence;
+  const useCase = new NotifySessionAbsence();
+  const result = await useCase.execute(sessionId, payload, user.id);
+
+  return resultJson(c, result);
+});
+
+export default route;