fix: 仅保留 Waffo，并修复调试包年误用永久 Product

调试不再把兼容字段 product_id 覆盖到包年；包年禁止回落永久商品；下单强制走 Waffo。

backend/internal/service/order/order_service.go

@@ -115,11 +115,14 @@ func (s *OrderService) CreateOrder(req dto.CreateOrderRequest, clientIP, userAge
 		return nil, fmt.Errorf("重复购买拦截: %s", checkResult.Reason)
 	}
 
-	// 4. 选取可用支付渠道（先选网关，写入订单） // Logan.Li
+	// 4. 仅对接 Waffo（禁用其它网关） // Logan.Li
 	var gateway model.PaymentGatewayConfig
-	if err := s.db.Where("enabled = ?", true).Order("priority ASC").First(&gateway).Error; err != nil {
-		return nil, errors.New("暂无可用的支付渠道")
+	if err := s.db.Where("gateway = ? AND enabled = ?", "waffo", true).First(&gateway).Error; err != nil {
+		return nil, errors.New("Waffo 支付未启用，请先在「支付」页配置")
 	}
+	_ = s.db.Model(&model.PaymentGatewayConfig{}).
+		Where("gateway <> ? AND enabled = ?", "waffo", true).
+		Updates(map[string]interface{}{"enabled": false, "priority": 100}).Error
 
 	notes := ""
 	if deviceID := strings.TrimSpace(req.DeviceID); deviceID != "" {
@@ -135,7 +138,7 @@ func (s *OrderService) CreateOrder(req dto.CreateOrderRequest, clientIP, userAge
 		Amount:         plan.Price,
 		Currency:       plan.Currency,
 		Status:         "pending",
-		PaymentGateway: gateway.Gateway,
+		PaymentGateway: "waffo",
 		ClientIP:       clientIP,
 		UserAgent:      userAgent,
 		Notes:          notes,
@@ -145,23 +148,17 @@ func (s *OrderService) CreateOrder(req dto.CreateOrderRequest, clientIP, userAge
 	}
 	_ = customersvc.AttachProduct(s.db, customer.ID, product.ID)
 
-	// 6. 生成收银台地址 // Logan.Li
-	var checkoutURL string
-	if gateway.Gateway == "waffo" {
-		url, err := payment.BuildCheckoutURL(
-			payment.LoadWaffoConfig(s.db),
-			order.OrderNo,
-			strings.TrimSpace(req.DeviceID),
-			req.CustomerEmail,
-			req.ReturnURL,
-			plan.PlanType,
-		)
-		if err != nil {
-			return nil, fmt.Errorf("Waffo 收银台配置错误: %v", err)
-		}
-		checkoutURL = url
-	} else {
-		checkoutURL = fmt.Sprintf("https://checkout.%s.com/?order_no=%s", gateway.Gateway, order.OrderNo)
+	// 6. 生成 Waffo 收银台地址 // Logan.Li
+	checkoutURL, err := payment.BuildCheckoutURL(
+		payment.LoadWaffoConfig(s.db),
+		order.OrderNo,
+		strings.TrimSpace(req.DeviceID),
+		req.CustomerEmail,
+		req.ReturnURL,
+		plan.PlanType,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("Waffo 收银台配置错误: %v", err)
 	}
 
 	return &dto.CreateOrderResponse{
@@ -170,7 +167,7 @@ func (s *OrderService) CreateOrder(req dto.CreateOrderRequest, clientIP, userAge
 		Amount:      plan.Price,
 		Currency:    plan.Currency,
 		Status:      "pending",
-		Gateway:     gateway.Gateway,
+		Gateway:     "waffo",
 		ExpiresAt:   time.Now().Add(30 * time.Minute).Format("2006-01-02 15:04:05"),
 	}, nil
 }