I haven't done anything other than a quick search, but it appears that there is a OAUTH2 module for Apache (on sourceforge).
There is also mod_auth_openidc (open ID connector) on Github.
Without having looked into either of these, I'm guessing, but I imagine they would allow you to put OAUTH in front of a tiddlywiki served through Apache (either directly or as a reverse proxy).
P.S. to answer your question, implementing OAUTH is surprisingly difficult as it involves 3 computers all talking to each-other (the desktop, the web server, and the oauth server).
P.P.S. I do see your point and I like your idea. Those with more solid programming skills than mine would have to decide if it is worth the effort to implement. Or, those with about my level of skill could figure out how to get one of the above apache modules working and do a write-up for us.
On Monday, January 7, 2019 at 11:37:15 AM UTC-5, @TiddlyTweeter wrote:
I wonder if we can OAuth logging on server versions?
The benefit is users don't need to create yet another login.
J