Add board service and repository, update routes and assets

- Introduced BoardService and BoardRepository for managing board-related data.
- Updated app routes to reflect the new board screen structure.
- Added new board-related assets to the asset manager.
- Refactored BoardScreen navigation to utilize the new provider structure.

lib/core/extensions/board_data_extension.dart

@@ -0,0 +1,12 @@
+import '../../data/services/model/board_response/board_response.dart';
+import '../enums/task_status.dart';
+
+extension BoardDataExtension on BoardData {
+  // تبدیل status string به TaskStatus enum
+  TaskStatus get statusEnum => TaskStatusExtension.fromString(status);
+
+  // کپی BoardData با status جدید
+  BoardData copyWithStatus(TaskStatus newStatus) {
+    return copyWith(status: newStatus.value);
+  }
+}