feat: implement support chat functionality with new module, service, controller, DTOs, and schema updates.

prisma/schema.prisma

@@ -75,6 +75,11 @@ enum MessageStatus {
   READ
 }
 
+enum SupportChatStatus {
+  OPEN
+  CLOSED
+}
+
 
 // ===========================================
 // USER - Authentication Only
@@ -135,6 +140,9 @@ model User {
   // Notifications
   notifications     Notification[]
 
+  // Support Chat
+  supportChats      SupportChat[]
+
   @@index([email])
   @@index([role])
   @@index([status])
@@ -572,3 +580,40 @@ model Testimonial {
   @@index([agentProfileId])
   @@map("testimonials")
 }
+
+// ===========================================
+// SUPPORT CHAT SYSTEM
+// ===========================================
+
+model SupportChat {
+  id               String            @id @default(uuid())
+  userId           String
+  status           SupportChatStatus @default(OPEN)
+  lastMessageAt    DateTime?
+  lastMessageText  String?           @db.VarChar(255)
+  userUnreadCount  Int               @default(0)
+  adminUnreadCount Int               @default(0)
+  createdAt        DateTime          @default(now())
+  updatedAt        DateTime          @updatedAt
+
+  user             User              @relation(fields: [userId], references: [id], onDelete: Cascade)
+  messages         SupportMessage[]
+
+  @@index([userId])
+  @@index([status])
+  @@map("support_chats")
+}
+
+model SupportMessage {
+  id          String      @id @default(uuid())
+  chatId      String
+  senderId    String
+  senderRole  String      // "USER" or "ADMIN"
+  content     String      @db.Text
+  createdAt   DateTime    @default(now())
+
+  chat        SupportChat @relation(fields: [chatId], references: [id], onDelete: Cascade)
+
+  @@index([chatId])
+  @@map("support_messages")
+}