백엔드 계약 문서 동기화하고 DTO 파서 정합성 확장

lib/features/masters/menu/data/dtos/menu_dto.dart

@@ -42,7 +42,7 @@ class MenuDto {
           : json['parent'] is Map<String, dynamic>
           ? MenuSummaryDto.fromJson(json['parent'] as Map<String, dynamic>)
           : null,
-      path: json['path'] as String?,
+      path: json['path'] as String? ?? json['route_path'] as String?,
       displayOrder: json['display_order'] as int?,
       isActive: (json['is_active'] as bool?) ?? true,
       isDeleted: (json['is_deleted'] as bool?) ?? false,