The success modal added a second click between the download button and
the file: request -> "下载链接已生成" popup -> 立即下载. Drop it and open
the generated relay link right away, keeping the previous new-tab
behaviour; a missing link still surfaces the error view.
- Replace renderSuccess with startDownload (anchor + target=_blank)
- Remove the popup-only CSS: alert, code-row, copy button, chips, meta
and the download action skin; error, cashier and scan-pay views keep
their styles
kate522