简化侧边栏菜单逻辑

- 移除单个子路由的特殊处理
- 统一使用children方式渲染菜单项
- 优化菜单结构，提升代码可维护性

web/src/layout/components/sidebar/components/SideMenu.vue

@@ -59,32 +59,10 @@ function getMenuItem(route, basePath = '') {
 
   if (!visibleChildren.length) return menuItem
 
-  if (visibleChildren.length === 1) {
-    // 单个子路由处理
-    const singleRoute = visibleChildren[0]
-    menuItem = {
-      ...menuItem,
-      label: singleRoute.meta?.title || singleRoute.name,
-      key: singleRoute.name,
-      path: resolvePath(menuItem.path, singleRoute.path),
-      icon: getIcon(singleRoute.meta),
-    }
-    const visibleItems = singleRoute.children
-      ? singleRoute.children.filter((item) => item.name && !item.isHidden)
-      : []
+  menuItem.children = visibleChildren
+    .map((item) => getMenuItem(item, menuItem.path))
+    .sort((a, b) => a.order - b.order)
 
-    if (visibleItems.length === 1) {
-      menuItem = getMenuItem(visibleItems[0], menuItem.path)
-    } else if (visibleItems.length > 1) {
-      menuItem.children = visibleItems
-        .map((item) => getMenuItem(item, menuItem.path))
-        .sort((a, b) => a.order - b.order)
-    }
-  } else {
-    menuItem.children = visibleChildren
-      .map((item) => getMenuItem(item, menuItem.path))
-      .sort((a, b) => a.order - b.order)
-  }
   return menuItem
 }