feat(channels): add Shangwutong connector

backend/internal/handler/api/v1/social_authorization.go

@@ -16,15 +16,11 @@ const instagramAuthorizationScope = "instagram_business_basic,instagram_business
 
 const tiktokAuthorizationScope = "user.info.basic,user.info.username,user.info.stats,user.info.profile,user.account.type,user.insights,message.list.read,message.list.send,message.list.manage"
 
-func authorizationReturnTo(c *gin.Context) string {
+func authorizationReturnTo(c *gin.Context, bodyValue string) string {
 	if value := strings.TrimSpace(c.Query("return_to")); value != "" {
 		return value
 	}
-	var payload struct {
-		ReturnTo string `json:"return_to" form:"return_to"`
-	}
-	_ = c.ShouldBind(&payload)
-	return strings.TrimSpace(payload.ReturnTo)
+	return strings.TrimSpace(bodyValue)
 }
 
 // TikTokAuthorizationRequest is the DTO for initiating TikTok OAuth flow
@@ -32,6 +28,7 @@ func authorizationReturnTo(c *gin.Context) string {
 type TikTokAuthorizationRequest struct {
 	AppID     string `json:"app_id"`
 	AppSecret string `json:"app_secret"`
+	ReturnTo  string `json:"return_to"`
 }
 
 func buildInstagramChatwootAuthorizationURL(accountID uint, returnTo string, appID, appSecret string) (string, error) {