I haven't managed to try this because the "select repo" does nothing on Ubuntu 24.04. It doesn't seem I can actually perform any action at all.

Odd okay, I got a separate report on Linux that the app crashes on startup. So for you, it launches fine, but the Select a repo button does nothing? This may sound weird, but have you waited ~1min to see if a file picker pops up?

Hm no, I didn't wait that long. Yep, no element did anything, it was as if the whole window were just an image, with no element responding to any sort of input.