task-10(壳层/路由): 实现页面级异步组件加载边界

lazy-config 暴露 loading 延迟/超时/文案与懒加载判定；lazy-page 用
defineAsyncComponent 提供 loading/error 组件，router 对所有注册路由统一包裹；
main.css 增加 .page-loading/.page-error 兜底样式。

admin-frontend-vue/src/router/index.ts

@@ -1,9 +1,10 @@
-import { createRouter, createWebHistory } from 'vue-router'
+import { createRouter, createWebHistory, type RouteRecordRaw } from 'vue-router'
 import type { AdminMenuNode } from '@/types/admin'
 import AdminLayout from '@/layout/AdminLayout.vue'
 import { useAdminSessionStore } from '@/stores/admin-session'
 import { APP_BASE_PATH } from '@/config/app'
 import { adminRouteRecords } from './routes'
+import { defineLazyPage } from './lazy-page'
 
 const router = createRouter({
   history: createWebHistory(APP_BASE_PATH),
@@ -11,7 +12,10 @@ const router = createRouter({
     {
       path: '/',
       component: AdminLayout,
-      children: adminRouteRecords,
+      children: adminRouteRecords.map((record) => ({
+        ...record,
+        component: defineLazyPage(record.component as () => Promise<{ default: unknown }>),
+      })) as RouteRecordRaw[],
     },
   ],
 })

admin-frontend-vue/src/router/lazy-config.ts

@@ -0,0 +1,15 @@
+/** 异步页面加载边界可调参数（任务 10）：loading 延迟/超时/文案。 */
+export const PAGE_LOADING_DELAY = 200
+export const PAGE_LOADING_TIMEOUT = 15000
+export const PAGE_LOADING_TEXT = '页面加载中'
+export const PAGE_LOAD_ERROR_TEXT = '页面加载失败，请刷新重试'
+
+/** 是否为异步加载器（函数式）。 */
+export function isLazyLoader(value: unknown): value is () => Promise<unknown> {
+  return typeof value === 'function'
+}
+
+/** 动态 import 产物是否为含 default 的页面模块。 */
+export function isPageModule(module: unknown): boolean {
+  return typeof module === 'object' && module !== null && 'default' in module
+}

admin-frontend-vue/src/router/lazy-page.ts

@@ -0,0 +1,23 @@
+import { defineAsyncComponent, h, type Component } from 'vue'
+import {
+  PAGE_LOADING_DELAY,
+  PAGE_LOADING_TEXT,
+  PAGE_LOADING_TIMEOUT,
+  PAGE_LOAD_ERROR_TEXT,
+} from './lazy-config'
+
+type PageLoader = () => Promise<{ default: unknown }>
+
+/**
+ * 页面级异步加载边界（任务 10）：按路由分包页面，加载中/失败都有明确反馈，
+ * 不把 chunk 加载错误静默吞掉。
+ */
+export function defineLazyPage(loader: PageLoader): Component {
+  return defineAsyncComponent({
+    loader: () => loader().then((mod) => mod.default as Component),
+    delay: PAGE_LOADING_DELAY,
+    timeout: PAGE_LOADING_TIMEOUT,
+    loadingComponent: () => h('div', { class: 'page-loading' }, PAGE_LOADING_TEXT),
+    errorComponent: () => h('div', { class: 'page-error' }, PAGE_LOAD_ERROR_TEXT),
+  })
+}