修复(#128): 统一续费场景促销判断

Co-authored-by: multica-agent <github@multica.ai>

internal/logic/public/order/purchaseLogic.go

@@ -129,13 +129,8 @@ func (l *PurchaseLogic) Purchase(req *types.PurchaseOrderRequest) (resp *types.P
 	// 防止不同套餐购买创建第二条订阅。
 	if !l.svcCtx.Config.Subscribe.SingleModel && orderType == 1 {
 		var existSub user.Subscribe
-		if e := l.svcCtx.DB.WithContext(l.ctx).
-			Model(&user.Subscribe{}).
-			Where("user_id = ? AND token != '' AND (order_id > 0 OR token LIKE 'iap:%')", entitlement.EffectiveUserID).
-			Order("expire_time DESC").
-			Order("updated_at DESC").
-			Order("id DESC").
-			First(&existSub).Error; e == nil && existSub.Id > 0 && existSub.Token != "" {
+		if e := paidSubscriptionQuery(l.ctx, l.svcCtx.DB, entitlement.EffectiveUserID).
+			First(&existSub).Error; e == nil && existSub.Id > 0 {
 			orderType = 2
 			parentOrderID = existSub.OrderId
 			subscribeToken = existSub.Token