API endpoint for user_saml to allow provisionning of SAML users

Hey, hello.

While creating a setup with a nextcloud instance with an SAML auth as single auth provider, we ran into a problem :

Any newly created in the IDP user are not visible in nextcloud, and are provisionned at the very first connection of the user on the platform.
There is already an API endpoint for creating nextcloud user but it works only for user that uses the basic nextcloud auth, not for the users that log in through SAML.

The firm I work for would like to add a provisioning SAML user API endpoint (in the exact same way it the createUserIfNotExists function do at first login).
It will be possible to provision user in the custom user_saml user table and allow the user to immediately exist in nextcloud without waiting to have him making his first log-on on the nextcloud instance.

If we add this API endpoint, would you be interested in accept such a merge request on the user_saml plugin? or should we develop a custom plugin (but that will more or less literally just re-use all the user_saml user creation process)?

Thanks,
Michel

Start by reading the existing user-creation API and the user_saml createUserIfNotExists flow described in the issue. Define how an API request would provision a SAML user in the user_saml table and how completion would be verified, then confirm the maintainers accept this scope before implementing it.