My local computer guy is fortunately still alive, and in business – the latter at least can be a bit of a craps shoot, these days – and was able to diagnosis the problem. Basically, my non-SSD drive decided to commit suicide. Thankfully, all of my creative work, including my books and ongoing writing projects, is on the SSD, because I was apparently smart several years ago and put them on the drive less likely to embrace the void*. Running around to resolve all of this ate up the day.
…Which wasn’t actually so bad. It was a nice day out to go driving around, and there’s plenty of greenery where I live. The hard part was internalizing the idea that I could just, you know, leave. I wasn’t on-call. The freedom was almost alarming.
*I have since made sure that my creative work has been freshly backed up on an external hard drive.