Oh my GOODNESS, it actually worked! Pushing files from the command line... worked! I made the edits to the local file, then pushed it via the command line (neocities push .) and it worked!
Flushed with this newfound skill, I've just downloaded nano and I'm editing this letter here instead of VS Code. Because why learnt to walk when you can run? And then trip over, smashing all your beautiful teeth in....
Anyway. More to come. I have some structural ideas for this page and I want to get those all sown up first. But we're making progress... It's exciting!