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

@@ -795,12 +795,12 @@ 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());
-            }
+        }
+        if (order.getPayPrice().equals(BigDecimal.ZERO)) {
+            order.setStatus(OrderStateEnum.PAID.getState());
+            order.setPayAt(new Date());
+        } else {
+            order.setStatus(OrderStateEnum.UNPAID.getState());
         }
 
         // coupon