"Download previous files" doesn't work the second time.

If I click to check files, I'm unable to resume downloading previous files, even when clicking the "Download previous files" button again.

To solve this currently, you have to delete and redownload the site before trying again.

Reproduce the flow by checking files, clicking "Download previous files," and clicking it again after the first attempt. Trace the UI entry point for that button and compare the second-click behavior with the initial download; done means previous files can be resumed without deleting and redownloading the site.

索引モデルが issue の本文から書いたものです。