feat: Nambahin feature notifikasi

prisma/schema.prisma

@@ -27,6 +27,7 @@ model Admin {
     professional_bio String? @db.Text
 
     projects Project[]
+    notifications Notification[]
 
     @@map("admin")
 }
@@ -195,6 +196,7 @@ model User {
     project_members  ProjectMember[]
     task_submissions TaskSubmission[]
     certificates     Certificate[]
+    notifications    Notification[]
 
     @@index([email])
     @@map("user")
@@ -347,3 +349,20 @@ model Certificate {
     @@index([id_user], map: "certificate_id_user_foreign")
     @@map("certificate")
 }
+
+model Notification {
+    id          Int      @id @default(autoincrement())
+    id_user     Int?     // For interns
+    id_admin    Int?     // For mentors/admins
+    title       String   @db.VarChar(255)
+    message     String   @db.Text
+    is_read     Boolean  @default(false)
+    created_at  DateTime @default(now())
+
+    user        User?    @relation(fields: [id_user], references: [id], onDelete: Cascade)
+    admin       Admin?   @relation(fields: [id_admin], references: [id], onDelete: Cascade)
+
+    @@index([id_user])
+    @@index([id_admin])
+    @@map("notification")
+}