> Expectations vs systemd/supervisord/tmux/dtach: where would you use this?

Sorry to be blunt, but I feel like this is a big unanswered question that you should be addressing. Why would I use your tool over the other well-known alternatives? I read through your overview and I don't see an answer.

You say that this is intended "for environments where you don’t want to stand up a full supervisor stack (or don’t have one)". And you compare it to systemd. But what Linux developer doesn't already have systemd installed?

Or to use a different comparison, what advantage does "fws run" have over "podman run"? Podman already supports PTYs that can be attached/detached, allows isolating different processes, and has an HTTP API.

It seems like you intend this for situations where you want a multi-pane text-base UI that resembles an IDE. But personally, I prefer to do this sort of thing by composing existing tools that provide that functionality (namely tmux/screen and Docker/Podman) rather than using a single integrated tool that tries to replace both.