fix: 布局horizontal-mix选择目录跳转首个子菜单

src/layouts/modules/global-menu/horizontal-mix-menu.vue

@@ -12,7 +12,10 @@ const { routerPushByKey } = useRouterPush();
 
 function handleSelectMixMenu(menu: App.Global.Menu) {
   setActiveFirstLevelMenuKey(menu.key);
-
+  // 选择首个子菜单
+  if (Array.isArray(menu.children) && menu.children.length > 0) {
+    routerPushByKey(menu.children[0].routeKey);
+  }
   if (!menu.children?.length) {
     routerPushByKey(menu.routeKey);
   }