FEAT: add authProvider field to user response

- Add authProvider to user entity DTO
- Update user service to include authProvider
- Update auth controller response

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/modules/users/dtos/entities.ts

@@ -64,6 +64,8 @@ export class UserNoRolesAndCustomer extends OmitType(UserNoRoles, [
 export class IUserByCustomer extends OmitType(User, ['customer']) {
   @ApiPropertyOptional()
   permissions?: string[];
+  @ApiPropertyOptional()
+  authProvider?: string;
 }
 
 export class CreateUserReq {

src/modules/users/users.service.ts

@@ -125,6 +125,7 @@ export class UsersService implements OnModuleInit {
       return { permissions };
     });
     res.user.permissions = permissions;
+    res.user.authProvider = process.env.AUTH_PROVIDER || 'cognito';
     return res;
   }