task-54(账号/权限页面): 实现后台菜单列表加载

menu-manage-model.ts 增 buildMenuManageTree 按 parentId 组装展示树(同级按 sort+name)；
menu-manage-api.ts GET /api/admin/permission-menus(menuType=admin) 扁平拉取并建树；
MenusPage 去内联 http，改走 adapter 展示默认展开树形菜单。8 用例全过，395 单测 + build 绿。

admin-frontend-vue/src/pages/account/MenusPage.vue

@@ -0,0 +1,47 @@
+<script setup lang="ts">
+import { onMounted, ref } from 'vue'
+import { ElMessage } from 'element-plus'
+import { loadMenuManageTree } from './menu-manage-api'
+import type { MenuManageNode } from './menu-manage-model'
+
+const loading = ref(false)
+const rows = ref<MenuManageNode[]>([])
+
+async function loadMenus() {
+  loading.value = true
+  try {
+    rows.value = await loadMenuManageTree()
+  } catch (error) {
+    ElMessage.error(error instanceof Error ? error.message : '菜单列表加载失败')
+  } finally {
+    loading.value = false
+  }
+}
+
+onMounted(loadMenus)
+</script>
+
+<template>
+  <div class="page-stack">
+    <div class="page-heading">
+      <div>
+        <h2>菜单管理</h2>
+        <p>维护后台菜单树和页面路由。权限粒度仅到菜单/页面。</p>
+      </div>
+      <el-button type="primary">新增菜单</el-button>
+    </div>
+    <el-card shadow="never">
+      <el-table v-loading="loading" :data="rows" row-key="id" default-expand-all stripe>
+        <el-table-column prop="name" label="菜单名称" min-width="220" />
+        <el-table-column prop="columnKey" label="权限标识" min-width="240" />
+        <el-table-column prop="routePath" label="路由" min-width="260" />
+        <el-table-column prop="sortOrder" label="排序" width="100" />
+        <el-table-column label="操作" width="140">
+          <template #default>
+            <el-button link type="primary">编辑</el-button>
+          </template>
+        </el-table-column>
+      </el-table>
+    </el-card>
+  </div>
+</template>