Booting uConsole CM4 from encrypted NVMe

I have a uConsole computer and a new NVMe adapter for it. I’m not going to walk around with a terabyte of unencrypted data. That wasn’t an option. I found several good HOWTOs for booting a uConsole off an encrypted NVMe drive, yet none of them worked well on their own. Each left out one essential detail or another. This is my mashup of those instructions. For testing, I wiped my NVMe drive and…