Home Assistant not restarting after reboot w. invalid configuration

My HA installation got into a very unhappy state - the web UI does not start, the console just shows

Waiting for the Home Assistant CLI to be ready...
[WARN] Home Assistant CLI not starting! Jump into emergency console...

How we got here - I have not updated HA for about six months and the HACS token had expired. Also, Pyscript needed an update. To update Pyscript, HACS needed a new token, so I updated the HACS token in configuration.yaml and then needed to reboot HA, but could not cleanly because the Pyscript configuration was not clean. Catch 22.

Perhaps foolishly I forced a restart, figuring HA would get itself restarted out, but it did not.

What can I do? I guess removing Pyscript from the CLI would bring back a clean system that would reboot?

So, I gave up wasting time on Googling and restored the instance from backup.

To anyone who reads this - the single most important add-on you must install is the Google Drive Backup. HA is pretty good, but continues to accommodate gotchas like this which can bork the entire system. These seem like edge cases but it is exactly this type of weakness that keeps HA as a niche technology for the tech-aware minority, rather than a product ready for the mass market. /gripe