fix(delivery): 将第一平台发货出站超时调到 30 秒

常态提交约 11 秒，15 秒上限会在上游偶发变慢时提前断开，可能把仍在处理的订单记成失败。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/service/delivery.go

@@ -29,6 +29,8 @@ const (
 	deliveryStageCreateOrder  = "create_upstream" // 创建上游正式订单失败
 
 	deliverySubmissionStaleTimeout = 10 * time.Minute
+	// 第一平台创建正式订单常态约 11 秒，15 秒上限会在偶发变慢时提前断开。
+	deliveryUpstreamTimeout = 30 * time.Second
 )
 
 // deliverySubmittedUpstream 判断订单是否已成功提交到上游正式订单。
@@ -79,7 +81,7 @@ func NewDeliveryService(fulfillment *FulfillmentService, bffBaseURL, channel, li
 	if linkTTLMinutes < 0 {
 		linkTTLMinutes = 0
 	}
-	client := &http.Client{Timeout: 15 * time.Second}
+	client := &http.Client{Timeout: deliveryUpstreamTimeout}
 	dlc := NewDLCProvider(bffBaseURL, channel, client)
 	router := NewFulfillmentRouter(dlc)
 	return &DeliveryService{

backend/internal/service/provider_dlc.go

@@ -41,7 +41,7 @@ func NewDLCProvider(bffBaseURL, channel string, httpClient *http.Client) *DLCPro
 		channel = "dlc"
 	}
 	if httpClient == nil {
-		httpClient = &http.Client{Timeout: 15 * timeSecond(15)}
+		httpClient = &http.Client{Timeout: deliveryUpstreamTimeout}
 	}
 	return &DLCProvider{
 		bffBaseURL: bffBaseURL,
@@ -633,6 +633,3 @@ func (p *DLCProvider) signProxy(path, method string, data interface{}, out inter
 	return lastErr
 }
 
-func timeSecond(s int) time.Duration {
-	return time.Duration(s) * time.Second
-}