Feature: Support OAuth2/OpenID for User Management

[LIRIKKER]

Is your feature request related to a problem? Please describe.
As a user, I would like to avoid managing usernames and passwords and instead use an OpenID provider I've already set up, specifically Authentik. This would reduce complexity and improve security by relying on existing identity providers.

Describe the solution you'd like
I would like user management and authentication to be handled by Authentik using OAuth2 or OpenID Connect (OIDC). Ideally, the integration would allow for the first user to log in via OAuth2 to be automatically assigned the admin role. This should also be compatible with the common OAuth2 authorization flows (Authorization Code, Implicit, etc.).

Describe alternatives you've considered
Traditional username/password management, but this introduces more overhead and security concerns compared to delegating to a trusted identity provider like Authentik. Other OAuth2 providers might be used, but Authentik is the one I've chosen for my setup.

Additional context
No other context.

[albinmedoc]

I would also love this feature.
I'm using Authentik which also supports OAuth2 and OIDC.