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/prisma/migrations/20260923120000_add_class_sessions_attendance/migration.sql

@@ -0,0 +1,68 @@
+-- CreateEnum
+CREATE TYPE "AttendanceStatus" AS ENUM ('PRESENT', 'ABSENT', 'EXCUSED');
+
+-- AlterTable
+ALTER TABLE "attendees" ADD COLUMN     "notifyToken" TEXT;
+
+-- CreateTable
+CREATE TABLE "class_sessions" (
+    "id" TEXT NOT NULL,
+    "groupId" TEXT NOT NULL,
+    "startsAt" TIMESTAMP(3) NOT NULL,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "class_sessions_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "attendances" (
+    "id" TEXT NOT NULL,
+    "attendeeId" TEXT NOT NULL,
+    "classSessionId" TEXT NOT NULL,
+    "status" "AttendanceStatus" NOT NULL,
+    "markedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "attendances_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "slot_releases" (
+    "id" TEXT NOT NULL,
+    "attendeeId" TEXT NOT NULL,
+    "classSessionId" TEXT NOT NULL,
+    "isClaimed" BOOLEAN NOT NULL DEFAULT false,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "slot_releases_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "class_sessions_groupId_startsAt_key" ON "class_sessions"("groupId", "startsAt");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "attendances_attendeeId_classSessionId_key" ON "attendances"("attendeeId", "classSessionId");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "slot_releases_attendeeId_classSessionId_key" ON "slot_releases"("attendeeId", "classSessionId");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "attendees_notifyToken_key" ON "attendees"("notifyToken");
+
+-- AddForeignKey
+ALTER TABLE "class_sessions" ADD CONSTRAINT "class_sessions_groupId_fkey" FOREIGN KEY ("groupId") REFERENCES "groups"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "attendances" ADD CONSTRAINT "attendances_attendeeId_fkey" FOREIGN KEY ("attendeeId") REFERENCES "attendees"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "attendances" ADD CONSTRAINT "attendances_classSessionId_fkey" FOREIGN KEY ("classSessionId") REFERENCES "class_sessions"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "slot_releases" ADD CONSTRAINT "slot_releases_attendeeId_fkey" FOREIGN KEY ("attendeeId") REFERENCES "attendees"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "slot_releases" ADD CONSTRAINT "slot_releases_classSessionId_fkey" FOREIGN KEY ("classSessionId") REFERENCES "class_sessions"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- Backfill: tokens de aviso de ausencia para alumnos existentes
+UPDATE "attendees" SET "notifyToken" = gen_random_uuid()::text WHERE "notifyToken" IS NULL;