Asset caching/proxying for increased user control/privacy

[vitaprimo]

Some of the UI of Home Assistant gets assets from the Internet. That includes for things that are already local/installed which hardly should warrant a connection to some server anywhere.

As ethical as a CDN or whatever the host might be, for privacy; it doesn't beat making no connections at all. Once things, such as integrations, are added, whatever assets needed for them that can be cached should be permanently cached. Otherwise it looks like this:

Furthermore, connections — ALL FRONTEND CONNECTIONS — should be proxied through Home Assistant itself even is it's more cumbersome or whatever the downsides so the user only has one or two source addresses to worry about at the firewall. Doing it on the browser it's kind of an underhanded and it's a less user-friendly method needed to manage them, thus undermining user's privacy when they have no control over them. Connections nowadays are so fast most users may not even realize these assets aren't self-hosted.

Frontend connections also make privacy extensions, such as uBlockOrigin, to show alerts because third party domains are contacted — or attempted to — which can't be a good look for privacy first Home Assistant.

Also, although this I guess might be backend-related, connectivity checking and other questionable connections such as user-invisible encrypted DNS should be manageable within the frontend.