fix: 修复非单订阅模式下过期用户重复购买产生双订阅的问题

1. purchaseLogic: 非单订阅模式下购买前查询已有订阅，路由为续费(type=2)
2. activateOrderLogic: 续费激活时触发节点分组重算，确保过期续费后权限生效

Co-Authored-By: claude-flow <ruv@ruv.net>

internal/logic/public/order/purchaseLogic.go

@@ -111,6 +111,26 @@ func (l *PurchaseLogic) Purchase(req *types.PurchaseOrderRequest) (resp *types.P
 		}
 	}
 
+	// 非单订阅模式下，若用户已有同套餐订阅（含过期），提前路由为续费，防止创建重复订阅
+	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 subscribe_id = ?", entitlement.EffectiveUserID, targetSubscribeID).
+			Order("expire_time DESC").
+			First(&existSub).Error; e == nil && existSub.Id > 0 && existSub.Token != "" {
+			orderType = 2
+			parentOrderID = existSub.OrderId
+			subscribeToken = existSub.Token
+			l.Infow("[Purchase] non-single mode purchase routed to renewal (existing subscription found)",
+				logger.Field("existing_subscribe_id", existSub.Id),
+				logger.Field("existing_status", existSub.Status),
+				logger.Field("user_id", u.Id),
+				logger.Field("subscribe_id", targetSubscribeID),
+			)
+		}
+	}
+
 	// 单订阅模式下，若已有同套餐 pending 订单，关闭旧单后继续创建新单（确保新单参数生效）
 	if l.svcCtx.Config.Subscribe.SingleModel && orderType == 1 {
 		var existPending order.Order

queue/logic/order/activateOrderLogic.go

@@ -895,6 +895,9 @@ func (l *ActivateOrderLogic) Renewal(ctx context.Context, orderInfo *order.Order
 		}
 	}
 
+	// Trigger user group recalculation (needed when renewing an expired subscription)
+	l.triggerUserGroupRecalculation(ctx, userInfo.Id)
+
 	// Clear user subscription cache
 	err = l.svc.UserModel.ClearSubscribeCache(ctx, userSub)
 	if err != nil {