feat(hjc): 后台订单退款接口 - POST /api/hjc/order/refund(置已退款+推送REFUNDED)

src/main/java/com/gxwebsoft/hjc/controller/HjcOrderController.java

@@ -202,6 +202,26 @@ public class HjcOrderController extends BaseController {
         return success(hjcOrderService.pageRel(param));
     }
 
+    @Operation(summary = "退款(标记已退款，幂等)，并推送 REFUNDED 状态")
+    @PostMapping("/refund")
+    public ApiResult<?> refund(@RequestBody Map<String, Object> body) {
+        String orderNo = body.get("orderNo") == null ? null : String.valueOf(body.get("orderNo"));
+        if (orderNo == null) {
+            return fail("订单号不能为空");
+        }
+        HjcOrder order = hjcOrderService.getByOrderNo(orderNo);
+        if (order == null) {
+            return fail("订单不存在");
+        }
+        if (order.getPayStatus() != null && order.getPayStatus() == 3) {
+            return success("已是退款状态", order);
+        }
+        order.setPayStatus(3);
+        hjcOrderService.updateById(order);
+        hjcBizService.pushOrderToOneStop(order);
+        return success("已退款", order);
+    }
+
     private String firstNotBlank(String a, String b) {
         return a != null && !a.trim().isEmpty() ? a : b;
     }