refactor(auth): restructure user schema for enhanced authentication

Author: Harxhit

apps/backend/prisma/schema.prisma

@@ -18,25 +18,60 @@ model User {
   company     String?
   avatarUrl   String?  @map("avatar_url")
   accentColor String   @default("#6366f1") @map("accent_color")
-  provider    String
-  providerId  String   @map("provider_id")
+  emailVerified Boolean @default(false) @map("email_verified") 
+  phoneNumber   String? @unique @map("phone_number")           
+  lastSignInAt  DateTime? @map("last_sign_in_at")           
   createdAt   DateTime @default(now()) @map("created_at")
   updatedAt   DateTime @updatedAt @map("updated_at")
+  isActive    Boolean  @default(false)
 
+  identities    UserIdentity[]   
+  refreshTokens RefreshToken[]   
   platformLinks PlatformLink[]
   cards         Card[]
   oauthTokens   OAuthToken[]
   ownedViews    CardView[]     @relation("cardOwner")
   viewedCards   CardView[]     @relation("cardViewer")
   followLogs    FollowLog[]
-  organizer     Event[]    
-  attendedEvents EventAttendee[] 
+  organizer     Event[]
+  attendedEvents EventAttendee[]
+  ownedTeams    Team[]         @relation("TeamOwner")
+  teamMemberships TeamMember[] @relation("TeamMember")
 
-  ownedTeams       Team[]          @relation("TeamOwner")
-  teamMemberships  TeamMember[]    @relation("TeamMember")
+  @@map("users")
+}
+
+model UserIdentity {
+  id         String   @id @default(uuid())
+  userId     String   @map("user_id")
+  provider   String   // "google.com" | "apple.com" | "firebase" | "phone"
+  providerId String   @map("provider_id")  // Google sub / Apple sub / Firebase UID
+  createdAt  DateTime @default(now()) @map("created_at")
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
 
   @@unique([provider, providerId])
-  @@map("users")
+  @@index([userId])
+  @@map("user_identities")
+}
+
+
+model RefreshToken {
+  id        String    @id @default(uuid())
+  userId    String    @map("user_id")
+  tokenHash String    @unique @map("token_hash") //SHA-256 hash
+  family    String    // token rotation
+  expiresAt DateTime  @map("expires_at")
+  revokedAt DateTime? @map("revoked_at")         // null = still valid
+  createdAt DateTime  @default(now()) @map("created_at")
+  userAgent String?   @map("user_agent")          
+  ip        String?
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@index([userId])
+  @@index([family])
+  @@map("refresh_tokens")
 }
 
 model PlatformLink {