add noti

lib/features/notifications/domain/entities/notification.dart

@@ -100,6 +100,32 @@ class Notification {
     return timeSinceCreated.inDays > 7;
   }
 
+  /// Get formatted time ago text (Vietnamese)
+  String get formattedTimeAgo {
+    final duration = timeSinceCreated;
+
+    if (duration.inMinutes < 1) {
+      return 'Vừa xong';
+    } else if (duration.inMinutes < 60) {
+      return '${duration.inMinutes} phút trước';
+    } else if (duration.inHours < 24) {
+      return '${duration.inHours} giờ trước';
+    } else if (duration.inDays == 1) {
+      return 'Hôm qua';
+    } else if (duration.inDays < 7) {
+      return '${duration.inDays} ngày trước';
+    } else if (duration.inDays < 30) {
+      final weeks = (duration.inDays / 7).floor();
+      return '$weeks tuần trước';
+    } else if (duration.inDays < 365) {
+      final months = (duration.inDays / 30).floor();
+      return '$months tháng trước';
+    } else {
+      final years = (duration.inDays / 365).floor();
+      return '$years năm trước';
+    }
+  }
+
   /// Copy with method for immutability
   Notification copyWith({
     String? notificationId,

lib/features/notifications/domain/repositories/notification_repository.dart

@@ -0,0 +1,32 @@
+/// Notification Repository Interface
+///
+/// Defines operations for managing notifications.
+library;
+
+import 'package:worker/features/notifications/domain/entities/notification.dart';
+
+/// Notification Repository
+///
+/// Provides methods to:
+/// - Fetch notifications (all, by category, unread)
+/// - Mark notifications as read
+/// - Get notification counts
+abstract class NotificationRepository {
+  /// Get all notifications
+  Future<List<Notification>> getAllNotifications();
+
+  /// Get notifications by category (general or order)
+  Future<List<Notification>> getNotificationsByCategory(String category);
+
+  /// Get unread notifications count
+  Future<int> getUnreadCount();
+
+  /// Mark notification as read
+  Future<void> markAsRead(String notificationId);
+
+  /// Mark all notifications as read
+  Future<void> markAllAsRead();
+
+  /// Refresh notifications (fetch from server)
+  Future<List<Notification>> refreshNotifications();
+}