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/menu-manage-model.ts

@@ -14,6 +14,7 @@ export interface MenuManageNode {
   menuType: string
   routePath: string
   sortOrder: number
+  children?: MenuManageNode[]
 }
 
 export interface MenuManageForm {
@@ -86,6 +87,37 @@ export function parseMenuManageList(payload: unknown): MenuManageNode[] {
     .filter((node): node is MenuManageNode => node !== null)
 }
 
+/** 按 parentId 组装展示树；同级按 (sortOrder,name) 升序，父缺失按根处理。 */
+export function buildMenuManageTree(items: MenuManageNode[]): MenuManageNode[] {
+  const nodes = new Map<number, MenuManageNode>()
+  for (const item of items) {
+    nodes.set(item.id, { ...item, children: [] })
+  }
+  const roots: MenuManageNode[] = []
+  for (const item of items) {
+    const node = nodes.get(item.id)
+    if (!node) continue
+    const parent = item.parentId === null ? undefined : nodes.get(item.parentId)
+    if (parent) {
+      parent.children!.push(node)
+    } else {
+      roots.push(node)
+    }
+  }
+  const order = (a: MenuManageNode, b: MenuManageNode) =>
+    a.sortOrder - b.sortOrder || a.name.localeCompare(b.name)
+  const sortRecursive = (nodes: MenuManageNode[]) => {
+    nodes.sort(order)
+    for (const node of nodes) node.children?.length && sortRecursive(node.children)
+  }
+  sortRecursive(roots)
+  for (const item of items) {
+    const node = nodes.get(item.id)
+    if (node && !node.children?.length) delete node.children
+  }
+  return roots
+}
+
 /** 新建/编辑表单空值工厂：默认菜单类型为 admin、排序 0、根父节点。 */
 export function emptyMenuManageForm(): MenuManageForm {
   return { name: '', columnKey: '', parentId: null, menuType: ADMIN_MENU_TYPE, routePath: '', sortOrder: 0 }