implement a secure auth layer

[MCLP2005]

Server side verification of login credentials.
Should be secure, maybe with encryption using SHA512 if possible with at least 50 rounds
Do not do this in middleware, but via the next.js API implementation options

Login credentials should be username/email and password.
2fa maybe in a later task

[MCLP2005]

This should also contain a registration page if the login using test data works as intended.

[MCLP2005]

auth should be on the whole domain using session tokens.
The login should only be valid for the session (cookie life time: SESSION)