发货链接返回完整域名：DELIVERY_BASE_URL 未配置时按请求 scheme+Host 推导

- GetOrCreateDeliveryLink/RestoreDeliveryLink 增加 requestBaseURL 参数
- buildDeliveryURL 优先级：DELIVERY_BASE_URL → 请求域名 → 路径
- 支持 X-Forwarded-Proto 与 TLS 判断 https

backend/internal/handler/open_v1.go

@@ -163,7 +163,7 @@ func (h *OpenV1Handler) GetDeliveryLink(c *gin.Context) {
 	openlog.SetAction(c, openlog.ActionQuery)
 	orderNo := c.Param("order_no")
 	openlog.Info(c, "delivery_link start order_no=%s", orderNo)
-	link, err := h.deliverySvc.GetOrCreateDeliveryLink(middleware.GetMerchantID(c), orderNo)
+	link, err := h.deliverySvc.GetOrCreateDeliveryLink(middleware.GetMerchantID(c), orderNo, requestBaseURL(c))
 	if err != nil {
 		openlog.Warn(c, "delivery_link fail order_no=%s err=%v", orderNo, err)
 		if sc, ok := err.(interface{ HTTPStatus() int }); ok {