I now decided I'll at least aim for some middle grounds: Rework #swad so it only needs a (server-side) #session once a user is #authenticated!

This does have some implications, e.g. passing a redirect argument to the authentication endpoint won't work any more. But experimentation shows a workaround would be to use an "internal redirect" to the login endpoint in #nginx.

We'll see where I end up. Having sessions only for authenticated users should reduce the need for server-side RAM significantly, so I hope 😉