将 6 组商品相关 App Service 接口/实现从 service/ 及 service/impl/ 移至 service/product/ 及 service/product/impl/： - CustomProductInfoService / CustomProductItemService - ProductTemplateInfoService / SysBillRuleService - LogCustomProductService / DiyUserService 纯移动+重命名，无逻辑变更。 Co-Authored-By: Claude <noreply@anthropic.com>
