feat: implement groups risk overview feature with analytics and routes

apps/backend/test/classes.test.ts

@@ -65,7 +65,7 @@ function makeSession(overrides: Record<string, unknown> = {}) {
   return {
     id: 'session-1',
     groupId: 'group-1',
-    startsAt: new Date('2026-09-23T19:00:00.000Z'),
+    startsAt: todayAtUtc(),
     group: {
       id: 'group-1',
       name: 'Funcional',
@@ -77,6 +77,13 @@ function makeSession(overrides: Record<string, unknown> = {}) {
   };
 }
 
+// Fecha "hoy" a las 19:00 UTC, del día real del runner.
+function todayAtUtc() {
+  const date = new Date();
+  date.setUTCHours(19, 0, 0, 0);
+  return date;
+}
+
 describe('classes routes', () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -85,7 +92,7 @@ describe('classes routes', () => {
 
   describe('GET /classes/today', () => {
     it('materializa y lista las clases de hoy del profesor', async () => {
-      const startsAt = new Date('2026-09-23T19:00:00.000Z');
+      const startsAt = todayAtUtc();
       prisma.group.findMany.mockResolvedValue([
         {
           id: 'group-1',
@@ -432,7 +439,7 @@ describe('classes routes', () => {
       })
         .format(new Date())
         .toUpperCase();
-      const startsAt = new Date('2026-09-23T19:00:00.000Z');
+      const startsAt = todayAtUtc();
 
       prisma.attendee.findUnique.mockResolvedValue({
         id: 'attendee-1',