feat: 订单列表接口返回明细items，不需要单独查询

src/main/java/com/example/building/service/impl/OrderServiceImpl.java

@@ -191,7 +191,18 @@ public class OrderServiceImpl implements OrderService {
             wrapper.le(Order::getCreatedAt, endDate);
         }
         wrapper.orderByDesc(Order::getCreatedAt);
-        return orderMapper.selectPage(pageParam, wrapper);
+        Page<Order> result = orderMapper.selectPage(pageParam, wrapper);
+        
+        // 查询每个订单的明细
+        if (result.getRecords() != null) {
+            for (Order order : result.getRecords()) {
+                List<OrderItem> items = orderItemMapper.selectList(
+                    new LambdaQueryWrapper<OrderItem>().eq(OrderItem::getOrderId, order.getOrderId()));
+                order.setItems(items);
+            }
+        }
+        
+        return result;
     }
 
     /**