However, I want to see if it's possible to create "micro-messenger" apps; basically, a messenger app that you only use with a handful of people[1]. I want to have full control over the server side, so please don't say "just use Signal".
Given Telegram's open-source base code, is it possible to create a decent messaging app that goes down when you also go down? (e.g., when you die, or when you just want to terminate it).
[1] I think if you're going to say something or share photos/files that are personal, chances are you are already close to your recipient. And there aren't many of those people.
I stumbled on this repo, might help you get a sense of how difficult it might be with this route and what features it would give you: https://github.com/spantaleev/matrix-docker-ansible-deploy
For the dead switch, you can `touch` a file weekly/daily/hourly. If that file's timestamp hasn't been updated, run your wipe script.