Add documentation for default menu visibility rules

- Add comment to getDefaultMenus() explaining menu visibility filtering
- Document that pagetype/workspace menus are System User only
- Document that App/Node/Agent marketplaces are System User only
- Ensure default menu documentation matches filtering logic

apps/jingrow/frontend/src/shared/stores/menu.ts

@@ -44,6 +44,10 @@ function saveToStorage(items: AppMenuItem[]) {
 }
 
 // 默认菜单，与现有路由对应
+// 注意：非 System User 用户只能看到部分菜单项（通过 visibleItems 过滤）
+// - pagetype 和 workspace 类型菜单仅对 System User 可见
+// - 开发分组下的应用市场、节点市场、智能体市场仅对 System User 可见
+// - 非 System User 只能看到工具市场
 function getDefaultMenus(): AppMenuItem[] {
   return [
     { id: 'dashboard', key: 'Dashboard', label: 'Dashboard', icon: 'tabler:dashboard', routeName: 'Dashboard', order: 1, type: 'route' },