preferably something with WOL that goes silent and fanless when not in use, or something I can shut down with a button

Recently I saw a Traefik plugin that can send WOL packets to a machine when a service that is hosted there gets a network request. It also shuts down the device when it’s not in use. You can set it up with a low power always on thing, like a rpi. I also have a buddy that set it up in a more diy way without Traefik so it’s definitely something that can be done and will save you a lot of electricity in the long term.