fix bug: 货拉拉因券id而导致的核价失败

common/components/delivery/services/DispatchService.php

@@ -1099,7 +1099,7 @@ class DispatchService
         foreach ($priceConditions as $condition) {
             $couponId = $condition['coupon_info']['coupon_id'] ?? null;
             if (!empty($couponId)) {
-                return $couponId;
+                return (string)$couponId; //转换为字符串，以免在传递过程中丢失精度（包括传递给前端时）
             }
         }