add dropdown

lib/features/users/domain/repositories/users_repository.dart

@@ -0,0 +1,16 @@
+import 'package:dartz/dartz.dart';
+
+import '../../../../core/errors/failures.dart';
+import '../entities/user_entity.dart';
+
+/// Abstract repository interface for users
+abstract class UsersRepository {
+  /// Get all users (from local storage if available, otherwise from API)
+  Future<Either<Failure, List<UserEntity>>> getUsers();
+
+  /// Sync users from API and save to local storage
+  Future<Either<Failure, List<UserEntity>>> syncUsers();
+
+  /// Clear all users from local storage
+  Future<Either<Failure, void>> clearUsers();
+}