Neat, but tbh I am very bearish on Python's future beyond APIs - templating html in Python is a terrible idea for anything larger than a hobby site, when you can have an API-first app with a React+Typescript frontend.
And if you need more than FastAPI, you might as well use django-ninja and get the full Django ecosystem at your disposal.
But it's also really not that difficult. Auth just takes a lot of practice for people to grok so most people don't want to touch it.
I'll open source something once we're done solving the problem cleanly at my company.
The actual authentication remains on the Django app, using the standard way of POSTing to a login form and receiving a session cookie -- only instead of a server-generated page serving a HTML form, you have the PWA lipstick sending data directly. This approach is so much simpler than dealing with id/access/refresh tokens, encryption keys, black lists, and all of the OIDC dance.
Use React and JSX (TSX, to be more specific). NextJS does good quality SSR, use that if you want an app that is also usable without JS.
Anybody not in that ecosystem /right now/ is going to be lagging behind by so much in velocity and capability, and will get eaten by competition.
I see the velocity, but high magnitude doesn't mean that you're going the right direction.