

I’d say use something like zeroconf(?) for local computer names. Or give them names in either your dns forwarder (router), hosts file or ssh config. Along with shell autocompletion, that might do the job. I use scp, rsync and I have a NFS share on the NAS and some bookmarks in Gnome’s file manager, so i just click on that or type in scp or rsync with the target computer’s name.
I use KaniDM and configured everything with OAuth2. That was the easiest and most straightforward I could find. But I don’t think they bothered implementing LDAP. Other platforms I tried are Authentik, Authelia, Keycloak, Zitadel… They’re all a bit heavier and have other/more features, but there wasn’t one I really fell in love with.