Is your feature request related to a problem? Please describe.

I have my photos in one place (on a network share) and a stationary PC (Windows) plus a laptop (Linux) from which I edit them with. It mostly works, but with the frustrations from #17512.

However, despite everything sometimes, out of thousands of photos edited a long time ago, dozens of skulls randomly show up from time to time.

The documentation for that is here but offering seemingly no solution other than to wipe thousands of thumbnails in order to re-regerate a few dozen.

Describe the solution you'd like
A button to re-generate all missing/skull thumbnails.

Alternatives

A button to re-generate all selected thumbnails.

Additional context

Opening the skulled photos once and then closing them re-generates the thumbnails but it's very tedious to do for dozens of photos.