[FEAT]: add OAuth server capabilities

### Description

Offering a decentralized authentication, decoupled and fully offline-capable.

* [oxide-auth-axum](https://github.com/HeroicKatora/oxide-auth/tree/master/oxide-auth-axum) might do the job.
* [openidconnect](https://github.com/ramosbugs/openidconnect-rs) looks also promising


### Additional Information

_No response_