功能：接入乐玩开放平台双渠道路由，并修复渠道锁定与 Webhook 可靠性

在保持 DLC 默认零破坏的前提下，支持 priority/仅乐玩/仅 DLC 履约策略与后台 GUI 配置；同步补齐 Prepare 渠道落库、乐玩订单取消、Webhook 验签与失败重试。

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

backend/cmd/server/main.go

@@ -10,6 +10,7 @@ import (
 	"affiliate_dash/internal/handler"
 	"affiliate_dash/internal/pkg/applog"
 	"affiliate_dash/internal/pkg/jwt"
+	"affiliate_dash/internal/pkg/lewan"
 	"affiliate_dash/internal/pkg/openlog"
 	"affiliate_dash/internal/pkg/timeutil"
 	"affiliate_dash/internal/router"
@@ -84,6 +85,18 @@ func main() {
 		cfg.DeliveryLinkTTLMinutes,
 	)
 
+	// 乐玩开放平台客户端与履约提供商注册
+	lewanClient := lewan.NewClient(lewan.Config{
+		BaseURL:       cfg.LewanBaseURL,
+		AccessKey:     cfg.LewanAccessKey,
+		SecretKey:     cfg.LewanSecretKey,
+		ApplicationID: cfg.LewanApplicationID,
+		WebhookSecret: cfg.LewanWebhookSecret,
+	}, nil)
+	lewanProvider := service.NewLewanProvider(lewanClient)
+	deliverySvc.RegisterProvider(lewanProvider)
+	fulfillmentSvc.SetUpstreamCancel(deliverySvc.CancelUpstream)
+
 	openlog.Init(cfg.OpenAPIDebug)
 
 	h := &router.Handlers{
@@ -105,6 +118,8 @@ func main() {
 		OpenAPIDebug:       cfg.OpenAPIDebug,
 		UploadDir:          cfg.UploadDir,
 		CORSAllowedOrigins: cfg.CORSAllowedOrigins,
+		LewanWebhook:       handler.NewLewanWebhookHandler(fulfillmentSvc, db, cfg.LewanWebhookSecret, cfg.LewanApplicationID),
+		PlatformLewan:      handler.NewPlatformLewanHandler(merchantSvc, lewanClient),
 	}
 
 	go callbackSvc.Run(context.Background())