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/enums/task_status.dart

@@ -0,0 +1,29 @@
+enum TaskStatus { toDo, inProgress, done }
+
+extension TaskStatusExtension on TaskStatus {
+  // تبدیل enum به string
+  String get value => name;
+
+  // تبدیل string به enum
+  static TaskStatus fromString(String? status) {
+    if (status == null) {
+      return TaskStatus.toDo;
+    }
+
+    return TaskStatus.values.firstWhere(
+      (e) => e.name == status,
+      orElse: () => TaskStatus.toDo,
+    );
+  }
+
+  String get displayNameEn {
+    switch (this) {
+      case TaskStatus.toDo:
+        return 'To Do';
+      case TaskStatus.inProgress:
+        return 'In Progress';
+      case TaskStatus.done:
+        return 'Done';
+    }
+  }
+}