task-7(壳层/路由): 根路由跳转到首个可见页面，移除硬编码默认页

helpers.firstVisiblePath 深度优先返回首个可路由页面，无页面返回空串；
store 增加 firstVisible；守卫在根路由/无权限时跳首个可见页，全部无页面则
停留根路由展示无菜单空态，删除 redirect:'/account/users' 硬编码。

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

@@ -0,0 +1,14 @@
+import type { AdminMenuNode } from '../types/admin'
+
+/**
+ * 取后端菜单树中第一个可路由页面路径（深度优先、保序）。
+ * 无任何可路由页面时返回空串，由调用方决定渲染空态或回根路由，不硬编码缺省页。
+ */
+export function firstVisiblePath(nodes: AdminMenuNode[] | null | undefined): string {
+  for (const node of nodes || []) {
+    if (node.route) return node.route
+    const nested = firstVisiblePath(node.children || [])
+    if (nested) return nested
+  }
+  return ''
+}

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

@@ -2,7 +2,6 @@ import { createRouter, createWebHistory } from 'vue-router'
 import type { AdminMenuNode } from '@/types/admin'
 import AdminLayout from '@/layout/AdminLayout.vue'
 import { useAdminSessionStore } from '@/stores/admin-session'
-import { findFirstRoute } from './helpers'
 import { APP_BASE_PATH } from '@/config/app'
 
 const router = createRouter({
@@ -12,7 +11,6 @@ const router = createRouter({
       path: '/',
       component: AdminLayout,
       children: [
-        { path: '', redirect: '/account/users' },
         { path: 'account/users', component: () => import('@/pages/account/UsersPage.vue'), meta: { menuKey: 'admin_users', title: '用户管理' } },
         { path: 'account/menus', component: () => import('@/pages/account/MenusPage.vue'), meta: { menuKey: 'admin_columns', title: '菜单管理' } },
         { path: 'account/groups', component: () => import('@/pages/account/GroupsPage.vue'), meta: { menuKey: 'admin_group_manage', title: '数据权限分组' } },
@@ -30,10 +28,14 @@ router.beforeEach(async (to) => {
       return false
     }
   }
-  if (to.path === '/') return findFirstRoute(session.menuTree)
+  // 根路由：有可见页面时跳到首个可见页；没有任何页面时停留根路由展示无菜单空态。
+  if (to.path === '/') {
+    return session.firstVisible || true
+  }
   const menuKey = to.meta.menuKey as string | undefined
   if (menuKey && !session.isSuperAdmin && !hasMenu(session.menuTree, menuKey)) {
-    return findFirstRoute(session.menuTree)
+    // 无权限页面：回退到首个可见页面；一个都没有则回根路由空态。
+    return session.firstVisible || '/'
   }
   return true
 })
@@ -43,6 +45,3 @@ function hasMenu(nodes: AdminMenuNode[], key: string): boolean {
 }
 
 export default router
-
-
-

admin-frontend-vue/src/stores/admin-session.ts

@@ -0,0 +1,43 @@
+import { defineStore } from 'pinia'
+import { fetchAdminMenuTree, fetchCurrentUser, logout } from '@/api/session'
+import type { AdminMenuNode, AdminUser } from '@/types/admin'
+import { firstVisiblePath } from '@/router/helpers'
+
+export const useAdminSessionStore = defineStore('admin-session', {
+  state: () => ({
+    user: null as AdminUser | null,
+    menuTree: [] as AdminMenuNode[],
+    initialized: false,
+    loading: false,
+    error: '',
+  }),
+  getters: {
+    isSuperAdmin: (state) => state.user?.role === 'super_admin',
+    firstVisible: (state): string => {
+      return firstVisiblePath(state.menuTree)
+    },
+  },
+  actions: {
+    async initialize() {
+      if (this.initialized || this.loading) return
+      this.loading = true
+      this.error = ''
+      try {
+        this.user = await fetchCurrentUser()
+        this.menuTree = await fetchAdminMenuTree()
+        this.initialized = true
+      } catch (error) {
+        this.error = error instanceof Error ? error.message : '后台初始化失败'
+        throw error
+      } finally {
+        this.loading = false
+      }
+    },
+    async signOut() {
+      await logout()
+      this.$reset()
+      window.location.assign('/login')
+    },
+  },
+})
+