added project repository

backend-dart/lib/domain/data/project_data_source.dart

@@ -1,34 +1,36 @@
 import 'package:backend_dart/domain/entities/project.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:fpdart/fpdart.dart';
 
 /// Interface for managing project data interactions.
 abstract class ProjectDataSource {
   /// Creates a new project in the data source.
   ///
   /// Throws an error if the creation fails.
-  Future<void> createProject(NewProject project);
+  TaskEither<IError, Project> createProject(ProjectCreate project);
 
   /// Retrieves a project by its unique ID.
   ///
   /// Returns `null` if no project is found.
-  Future<Project?> findProjectById(String id);
+  TaskEither<IError, Project>  findProjectById(String id);
 
   /// Retrieves all projects associated with a specific user.
   ///
   /// Returns an empty list if no projects are found.
-  Future<List<Project>> findProjectsByUserId(String userId);
+  TaskEither<IError,List<Project>> findProjectsByUserId(String userId);
 
   /// Updates an existing project in the data source.
   ///
   /// Throws an error if the update fails.
-  Future<void> updateProject(ProjectUpdate project);
+  TaskEither<IError, Project> updateProject(ProjectUpdate project);
 
   /// Deletes a project by its unique ID.
   ///
   /// Throws an error if the deletion fails.
-  Future<void> deleteProject(String id);
+  TaskEither<IError, Project>  deleteProject(String id);
 
   /// Retrieves all projects in the data source.
   ///
   /// Returns an empty list if no projects exist.
-  Future<List<Project>> findAllProjects();
+  TaskEither<IError, List<Project>> findAllProjects();
 }