update phone schema

Backend/src/services/auth.service.ts

@@ -58,7 +58,7 @@ export class AuthService {
      * User registration
      */
     async register(data: RegisterRequest): Promise<RegisterResponse> {
-        const { username, email, password, first_name, last_name, prefix } = data;
+        const { username, email, password, first_name, last_name, prefix, phone } = data;
 
         // Check if username already exists
         const existingUsername = await prisma.user.findUnique({
@@ -78,6 +78,15 @@ export class AuthService {
             throw new ValidationError('Email already exists');
         }
 
+        // Check if phone number already exists
+        const existingPhone = await prisma.user.findUnique({
+            where: { phone }
+        });
+
+        if (existingPhone) {
+            throw new ValidationError('Phone number already exists');
+        }
+
         // Get STUDENT role
         const studentRole = await prisma.role.findUnique({
             where: { code: 'STUDENT' }