docs: explain navigation, search and content components

app/components/BackendNavigation.vue

@@ -1,4 +1,5 @@
 <script>
+// 加载共享导航状态并渲染菜单；仅在组件仍挂载且已加载完成时向布局通知结果。
 import "~/assets/styles/BackendNavEntry.Bx6IPica.css";
 import "~/assets/styles/BackendNavigation.CEj4LnzI.css";
 import { renderList } from "vue";
@@ -45,6 +46,7 @@ var y = {
           onBeforeUnmount(() => {
             O = !1;
           });
+          // 已有错误时允许重新加载；把是否为后台权威配置一并交给父级判断。
           async function k() {
             (await C.load(!!E.value),
               O && D.value && x(`loaded`, w.value, C.authoritative.value));