This is interesting - maybe it's time I use flakes...

We have an issue to support non flake deployments: https://github.com/nlewo/comin/issues/30

If you want a basic version of this you can just use the built-in

  system.autoUpgrade = {
    enable = true;
    flake = "github:you/dotfiles";
  };

Is this named from the overweight cat meme?

No, it has been initially developed to manage a "COMmunity INfrastructure" and it sounds like the word "coming". I didn't know this meme but it's a nice coincidence because this infrastructure is actually a kind of "CHATONS" [1] (kitten in french)! Thx for the ref which could be useful for a future logo!

[1] https://www.chatons.org/en