fix(order): 修复零元订单状态设置逻辑

- 将订单状态设置逻辑移出 promo code块
- 确保所有支付价格为零的订单都设置为已支付状态

src/main/java/com/ycwl/basic/service/pc/impl/OrderServiceImpl.java

@@ -795,13 +795,13 @@ public class OrderServiceImpl implements OrderService {
             order.setPrice(cachedResult.getFinalAmount());
             // promo code
             order.setPayPrice(cachedResult.getFinalAmount());
+        }
         if (order.getPayPrice().equals(BigDecimal.ZERO)) {
             order.setStatus(OrderStateEnum.PAID.getState());
             order.setPayAt(new Date());
         } else {
             order.setStatus(OrderStateEnum.UNPAID.getState());
         }
-        }
 
         // coupon
         order.setCouponPrice(BigDecimal.ZERO);