Anytype is local/offline first, P2P, end to end encrypted, open source, and has a great mobile app. They provide a (storage limited) cloud backup peer for free. You can either self host that yourself, or just rely on P2P syncing with your other devices. I’ve been using it for years and really like it.

https://anytype.io/

Not audio specific but…

Shelly products (smart relays, plugs, sensors, etc.) all work over local network control and I’ve been very happy with them. I have a bunch throughout the house, and they are all denied internet access at the network level.

Also, all HomeKit devices must, by the specification, allow local control. You should be able to use those devices locally using the Home Assistant HomeKit Device integration without having any Apple devices. My Ecobee thermostats work great through this integration even though they are also denied internet access.

Good luck, and have fun nerding out on your new home!

You only pay if you want to use > 1GB of their cloud storage, which you wouldn’t if you self-hosted it or relied entirely on P2P syncing.

https://anytype.io/pricing

Anytype: Free, open source, offline first, P2P sync, end to end encrypted.