Signal bot

I'd like to be able to send a Signal message back to Haven to confirm if it's activated.

This idea could be expanded to implement a full bot that lets you trigger taking photos, recording audio, etc. remotely, but I think there should be discussion about whether or not this is actually a good idea.

But to begin with, just one command that tells you if it's activated would be a good start.

The issue names no files, tests, or entry points; first locate Haven's existing Signal messaging and activation-status handling. Done means one Signal command can report whether Haven is activated, while the broader remote-control bot remains subject to discussion.

Written by the indexing model from the issue text.