remove phone from user

Backend/src/services/auth.service.ts

@@ -81,8 +81,8 @@ export class AuthService {
             throw new ValidationError('Email already exists');
         }
 
-        // Check if phone number already exists
-        const existingPhone = await prisma.user.findUnique({
+        // Check if phone number already exists in user profiles
+        const existingPhone = await prisma.userProfile.findFirst({
             where: { phone }
         });