退款审核功能：待交接取消不再自动退款，改为客服审核后原路退回

- 租客在待交接状态取消订单不再自动退款，改为 refund_status=pending_review
- 新增退款审核页面 /admin/orders/refund-review，客服可逐个审核
- 新增 POST /refund/approve 通过退款、POST /refund/reject 驳回退款
- 新增 GET /orders/refund-pending 查询待审核退款订单列表
- 优化状态标签表述：已取消→租客已取消、已关闭→客服已关闭、异常→客服介入
- 新增 refund_status: pending_review 及其前端标签「待客服审核退款」
- AdminOrderDetailView 退款状态改用统一 refundStatusLabel

frontend/src/router/adminRoutes.ts

@@ -30,6 +30,12 @@ export const adminRoutes: RouteRecordRaw[] = [
     component: () => import('@/features/admin/views/AdminOrdersView.vue'),
     meta: adminMeta,
   },
+  {
+    path: adminPath('orders/refund-review'),
+    name: 'admin-refund-review',
+    component: () => import('@/features/admin/views/AdminRefundReviewView.vue'),
+    meta: adminMeta,
+  },
   {
     path: adminPath('orders/:id'),
     name: 'admin-order-detail',