They were put there by a man!

K9 is not a Thunderbird fork, it was created as it's own thing. Recently it's been picked up by Mozilla to become Thunderbird for android with the original creator still on board.

None of these are my daily driver, FWIW I use Pop!

Lord of War

Mew has good taste in repairable laptops.

THEY WERE PUT THERE BY A MAN...

Yes, here is the link to their Liftoff's GitHub https://github.com/liftoff-app/liftoff

License is listed as GPL-2.0

If you prefer to use docker compose you can write your own docker-compose.yml file like I did.

version: "3"

services:
  wefwef:
    container_name: wefwef
    image: ghcr.io/aeharding/wefwef:latest
    ports:
      - 5314:5314
    restart: unless-stopped # remove this is you don't want wefwef to run always

You should be able to access wefwef with http://localhost:5314 if you're running on your local machine, or if you have it running on something else access it with http://<ip address>:5314.