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/setting/setting_service.go

@@ -256,8 +256,8 @@ func (s *SettingService) UpdateWaffo(req dto.WaffoSettingsUpdate) (*dto.WaffoSet
 		return nil, errors.New("保存 Waffo 配置失败")
 	}
 	_ = s.db.Model(&model.PaymentGatewayConfig{}).
-		Where("gateway <> ? AND enabled = ?", "waffo", true).
-		Update("priority", 100).Error
+		Where("gateway <> ?", "waffo").
+		Updates(map[string]interface{}{"enabled": false, "priority": 100}).Error
 
 	return s.GetWaffo()
 }
@@ -281,9 +281,10 @@ func (s *SettingService) DebugWaffo(req dto.WaffoDebugRequest) *dto.WaffoDebugRe
 	if planType == "" {
 		planType = "yearly"
 	}
-	productID := strings.TrimSpace(req.ProductID)
+	// 按计划解析 Product；忽略兼容字段 product_id（常为永久商品，会污染包年调试） // Logan.Li
+	productID := payment.ResolveProductID(cfg, planType)
 	if productID == "" {
-		productID = payment.ResolveProductID(cfg, planType)
+		productID = strings.TrimSpace(req.ProductID)
 	}
 
 	authMode := "none"