统一管理后台分页样式

- 新建 AdminTablePagination 组件，统一分页 UI
- 改造 6 个前端页面使用统一分页组件：
  - 管理员管理
  - 用户管理
  - 申诉管理
  - 审计日志
  - 公告管理
  - 钱包流水
- 订单管理前后端完整改造：
  - 后端：添加 PaginatedResult 结构，支持 page/page_size 参数
  - 前端：API 支持分页参数，页面使用统一分页组件
- 所有列表页分页样式统一为商品管理的 .table-pagination 设计

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/features/admin/views/AdminOrdersView.vue

@@ -1,17 +1,34 @@
 <script setup lang="ts">
-import { computed, ref } from 'vue'
+import { computed, onMounted, ref } from 'vue'
 
 import { fetchAdminOrders, type Order } from '@/features/orders'
-import { useAdminTable } from '@/features/admin/composables/useAdminTable'
 import { handoffStatusLabel, orderStatusLabel, settlementStatusLabel } from '@/utils/statusLabels'
 import { formatDateTime } from '@/utils/time'
+import AdminTablePagination from '../components/AdminTablePagination.vue'
 
 const status = ref('')
+const loading = ref(false)
+const orders = ref<Order[]>([])
+const total = ref(0)
+const currentPage = ref(1)
+const currentPageSize = ref(20)
 
-const { loading, data: orders, load: loadOrders } = useAdminTable<Order[]>({
-  fetchFn: fetchAdminOrders,
-  initialData: [],
-})
+onMounted(loadOrders)
+
+async function loadOrders() {
+  loading.value = true
+  try {
+    const result = await fetchAdminOrders(currentPage.value, currentPageSize.value)
+    orders.value = result.items
+    total.value = result.total
+  } finally {
+    loading.value = false
+  }
+}
+
+async function handlePageChange() {
+  await loadOrders()
+}
 
 const filteredOrders = computed(() => {
   if (!status.value) return orders.value
@@ -74,5 +91,14 @@ const filteredOrders = computed(() => {
         </template>
       </el-table-column>
     </el-table>
+
+    <AdminTablePagination
+      v-if="total > 0"
+      v-model:current-page="currentPage"
+      v-model:page-size="currentPageSize"
+      :total="total"
+      :loading="loading"
+      @page-change="handlePageChange"
+    />
   </section>
 </template>