feat: 重构后台路由并使用嵌套路由；添加图片上传功能

- 拆分 AdminView 为多个子页面组件，使用嵌套路由
- 拆分 MerchantView 为多个子页面组件，使用嵌套路由
- 创建 AdminLayout 和 MerchantLayout 布局组件
- 修复编译错误：IconSend 重复导入、IconDatabase 不存在
- 修复 HomeView 缺失 onMounted 导入
- 添加文件上传后端接口和静态资源映射
- 为商品和轮播图添加图片上传功能（支持预览、清除）

frontend/src/router/index.js

@@ -5,8 +5,30 @@ import CartView from '../views/CartView.vue'
 import OrdersView from '../views/OrdersView.vue'
 import FavoritesView from '../views/FavoritesView.vue'
 import ProfileView from '../views/ProfileView.vue'
-import AdminView from '../views/AdminView.vue'
-import MerchantView from '../views/MerchantView.vue'
+
+// Admin Layout & Pages
+import AdminLayout from '../views/admin/AdminLayout.vue'
+import AdminOverview from '../views/admin/AdminOverview.vue'
+import AdminOrders from '../views/admin/AdminOrders.vue'
+import AdminRisk from '../views/admin/AdminRisk.vue'
+import AdminProducts from '../views/admin/AdminProducts.vue'
+import AdminAudit from '../views/admin/AdminAudit.vue'
+import AdminUsers from '../views/admin/AdminUsers.vue'
+import AdminBanners from '../views/admin/AdminBanners.vue'
+import AdminReviews from '../views/admin/AdminReviews.vue'
+import AdminLogistics from '../views/admin/AdminLogistics.vue'
+import AdminInventory from '../views/admin/AdminInventory.vue'
+import AdminProfile from '../views/admin/AdminProfile.vue'
+
+// Merchant Layout & Pages
+import MerchantLayout from '../views/merchant/MerchantLayout.vue'
+import MerchantOverview from '../views/merchant/MerchantOverview.vue'
+import MerchantProducts from '../views/merchant/MerchantProducts.vue'
+import MerchantOrders from '../views/merchant/MerchantOrders.vue'
+import MerchantReviews from '../views/merchant/MerchantReviews.vue'
+import MerchantLogistics from '../views/merchant/MerchantLogistics.vue'
+import MerchantInventory from '../views/merchant/MerchantInventory.vue'
+import MerchantProfile from '../views/merchant/MerchantProfile.vue'
 
 const routes = [
   { path: '/', redirect: '/products' },
@@ -16,9 +38,43 @@ const routes = [
   { path: '/favorites', component: FavoritesView },
   { path: '/profile', component: ProfileView },
   { path: '/login', component: LoginView },
-  { path: '/admin', component: AdminView },
-  { path: '/merchant', component: MerchantView },
-  { path: '/customer', redirect: '/products' }
+  { path: '/customer', redirect: '/products' },
+  
+  // Admin Routes
+  {
+    path: '/admin',
+    component: AdminLayout,
+    redirect: '/admin/overview',
+    children: [
+      { path: 'overview', name: 'admin-overview', component: AdminOverview },
+      { path: 'orders', name: 'admin-orders', component: AdminOrders },
+      { path: 'risk', name: 'admin-risk', component: AdminRisk },
+      { path: 'products', name: 'admin-products', component: AdminProducts },
+      { path: 'audit', name: 'admin-audit', component: AdminAudit },
+      { path: 'users', name: 'admin-users', component: AdminUsers },
+      { path: 'banners', name: 'admin-banners', component: AdminBanners },
+      { path: 'reviews', name: 'admin-reviews', component: AdminReviews },
+      { path: 'logistics', name: 'admin-logistics', component: AdminLogistics },
+      { path: 'inventory', name: 'admin-inventory', component: AdminInventory },
+      { path: 'profile', name: 'admin-profile', component: AdminProfile }
+    ]
+  },
+  
+  // Merchant Routes
+  {
+    path: '/merchant',
+    component: MerchantLayout,
+    redirect: '/merchant/overview',
+    children: [
+      { path: 'overview', name: 'merchant-overview', component: MerchantOverview },
+      { path: 'products', name: 'merchant-products', component: MerchantProducts },
+      { path: 'orders', name: 'merchant-orders', component: MerchantOrders },
+      { path: 'reviews', name: 'merchant-reviews', component: MerchantReviews },
+      { path: 'logistics', name: 'merchant-logistics', component: MerchantLogistics },
+      { path: 'inventory', name: 'merchant-inventory', component: MerchantInventory },
+      { path: 'profile', name: 'merchant-profile', component: MerchantProfile }
+    ]
+  }
 ]
 
 const router = createRouter({
@@ -26,4 +82,4 @@ const router = createRouter({
   routes
 })
 
-export default router
+export default router