I’d like to do the same, but atm I use nginx to serve all the web interfaces… And keycloak support is either a plus subscription feature or made to work with hacky Lua scripts.
So for now it’s security through obscurity, I got a wildcard cert and the pages are accessed based on subdomain. So afaik nobody has a clue unless they start iterating common subdomain names. (At some point™️ I’m adding proper auth though)
With proper open protocols for communication with various services such a ‘everything’ app could become a thing at some point.
Where I live we already have a single app (owned for a large part by the govt) we can use to log in to most official services, and any decent-size service can apply to offer log in using it. Going from that concept it really isn’t too much of a stretch to an “everything app” becoming a thing.