Round 19: Professional Notebooks, Digital Rewards, GDPR, Role-Based Dashboard, Deep Styling Polish

- Fixed attendance API 403: added TEACHER school membership check
- Fixed competitions API 403: cross-school access, null schoolId, public fallback
- Fixed GDPR export API 500: 16 Prisma field name mismatches
- Enhanced notebooks: page templates (Cornell, Mind Map, Venn, T-Chart, Weekly Planner),
  sticky notes, search, page duplication, sections/chapters, highlighter tool
- Added scratch pad with DrawingCanvas in assessments for hand-written solutions
- Role-based dashboard: TEACHER (competence radar, upcoming lessons),
  STUDENT (grades trend, competitions), PARENT (children grades, calendar),
  SCHOOL_ADMIN (system health, audit log, user management)
- Digital reward system: 16 demo rewards, points earning/redemption,
  categories (streaming, shopping, experiences, merchandise, privileges)
- GDPR compliance: consent management, data retention, cookie consent
- Deep styling polish: glassmorphism, gradient headers, animated sidebar,
  card hover effects, progress bar animations, timeline dots, FAB button
- 160+ new i18n keys (DE/EN)

prisma/schema.prisma

@@ -76,6 +76,8 @@ model School {
   newsletters        Newsletter[]
   competitions       Competition[]
   rewardClaims       RewardClaim[]
+  rewards            Reward[]
+  rewardPoints       RewardPoints[]
   subjectTopics      SubjectTopic[]
   district           SchoolDistrict? @relation(fields: [districtId], references: [id])
   districtId         String?
@@ -128,6 +130,8 @@ model User {
   competitionsCreated       Competition[]
   competitionParticipations CompetitionParticipant[]
   competitionClaims         RewardClaim[]
+  rewardRedemptions         RewardRedemption[]
+  rewardPoints              RewardPoints[]
   studentAnswers            StudentAnswer[]
 }
 
@@ -1845,3 +1849,66 @@ model StudentAnswer {
   @@index([studentId])
   @@map("student_answers")
 }
+
+// ─── Digital Reward Catalog & Points System ──────────────────────────
+
+model Reward {
+  id          String   @id @default(cuid())
+  schoolId    String
+  title       String
+  description String?
+  category    String   // streaming, shopping, experience, merchandise, privilege
+  pointsCost  Int
+  image       String?
+  stock       Int?
+  isActive    Boolean  @default(true)
+  isDemo      Boolean  @default(false)
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+  deletedAt   DateTime?
+
+  school     School   @relation(fields: [schoolId], references: [id])
+  redemptions RewardRedemption[]
+
+  @@index([schoolId])
+  @@index([category])
+  @@map("rewards")
+}
+
+model RewardRedemption {
+  id          String   @id @default(cuid())
+  rewardId    String
+  userId      String
+  pointsSpent Int
+  status      String   @default("pending") // pending, approved, rejected, fulfilled
+  note        String?
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+
+  reward      Reward   @relation(fields: [rewardId], references: [id])
+  user        User     @relation(fields: [userId], references: [id])
+
+  @@index([rewardId])
+  @@index([userId])
+  @@index([status])
+  @@map("reward_redemptions")
+}
+
+model RewardPoints {
+  id          String   @id @default(cuid())
+  userId      String
+  schoolId    String
+  points      Int      @default(0)
+  source      String   // competition, grade, attendance, homework
+  sourceId    String?  // ID of the source entity
+  description String?
+  createdAt   DateTime @default(now())
+
+  user        User     @relation(fields: [userId], references: [id])
+  school      School   @relation(fields: [schoolId], references: [id])
+
+  @@index([userId])
+  @@index([schoolId])
+  @@index([source])
+  @@map("reward_points")
+}