Integrate as a real companion app

[cassidyjames]

All the APIs are open source, so it should be possible to have Butler show up as an actual companion app with all the plumbing to handle exposing certain device sensors, receiving notifications, etc.

This is probably going to become an overarching issue to track the progress, and individual companion app features can be tracked as their own individual issues.

[mar-v-in]

I'm linking this here as a reference (and happy user): https://github.com/tobias-kuendig/hacompanion

[scottsweb]

Some related projects that might provide a head start:

• https://flathub.org/apps/io.github.bkbilly.lnxlink / https://bkbilly.gitbook.io/lnxlink
• https://system-bridge.timmo.dev/