HTML and NXML need to overwrite old ones; are blank
When I click "Regenerate previews", NXML and HTML files are uploaded to the manuscript, but they are blank.
Also, the uploaded NXML and HTML should overwrite any old ones—there should only be one of each at a time. After speaking to the helpdesk about how this should work, ideally they would even keep the same IDs—so if there are already 'tempHTML' and 'PMCfinal' files on the manuscript, we would keep all the other DB file table data for these and just update with the new file's minio URL.