I use a Mammotion Mini for my backyard which I got at a pretty big discount during Memorial Day sales. I don’t have HA, but it seems there’s some work going on for integration: https://community.home-assistant.io/t/mammotion-luba-integration/604662/63.
It does require internet access though, and I put it in my isolated guest vlan to be safe. I haven’t tried running it without an internet connection yet. Obviously this doesn’t meet all your requirements, but I can at least attest that the mower itself is pretty good. Good luck on your search!
I have the same bluetooth keyboard. lol