fix(shopOrder): 支持订单拒绝退款状态校验

- 修改退款操作接口，增加对拒绝退款状态（orderStatus=5）的支持
- 更新接口描述，明确支持申请、拒绝、同意及客户端申请退款四种状态
- 优化校验逻辑，确保orderStatus只能为4、5、6或7
- 完善参数非空判断并返回相应失败信息

src/main/java/com/gxwebsoft/shop/controller/ShopOrderController.java

@@ -441,14 +441,15 @@ public class ShopOrderController extends BaseController {
     }
 
     @PreAuthorize("hasAuthority('shop:shopOrder:refund')")
-    @Operation(summary = "订单退款操作(申请退款/同意退款)", description = "orderStatus=4 申请退款；orderStatus=6 同意退款并发起原路退款")
+    @Operation(summary = "订单退款操作(申请退款/同意退款/拒绝退款)", description = "orderStatus=4 申请退款；orderStatus=5 拒绝退款；orderStatus=6 同意退款并发起原路退款；orderStatus=7 客户端申请退款")
     @PutMapping("/refund")
     public ApiResult<?> refund(@RequestBody ShopOrder req) {
       if (req == null || req.getOrderId() == null || req.getOrderStatus() == null) {
         return fail("orderId 和 orderStatus 不能为空");
       }
-        if (!Objects.equals(req.getOrderStatus(), 4) && !Objects.equals(req.getOrderStatus(), 6) && !Objects.equals(req.getOrderStatus(), 7)) {
-            return fail("orderStatus 仅支持 4(申请退款) 或 6(同意退款) 或 7(客户端申请退款)");
+      if (!Objects.equals(req.getOrderStatus(), 4) && !Objects.equals(req.getOrderStatus(), 5)
+        && !Objects.equals(req.getOrderStatus(), 6) && !Objects.equals(req.getOrderStatus(), 7)) {
+        return fail("orderStatus 仅支持 4(申请退款)、5(拒绝退款)、6(同意退款)、7(客户端申请退款)");
       }
 
         ShopOrder current = shopOrderService.getById(req.getOrderId());