重构扑克牌设计系统：修复后端渲染bug，重写前端编辑器

backend/apps/projects/urls.py

@@ -1,9 +1,13 @@
 from django.urls import path
-from .views import project_list, project_detail, asset_list, asset_detail
+from .views import (
+    project_list, project_detail, project_save_design,
+    asset_list, asset_detail,
+)
 
 urlpatterns = [
     path('', project_list, name='project-list'),
     path('<str:pk>/', project_detail, name='project-detail'),
+    path('<str:pk>/design/', project_save_design, name='project-save-design'),
     path('<str:project_pk>/assets/', asset_list, name='asset-list'),
     path('<str:project_pk>/assets/<str:asset_pk>/', asset_detail, name='asset-detail'),
 ]