As an admin user I would like to limit sign up to a specified domain

Q1. What is the problem that you are trying to solve?
As an admin user I would like to limit user registrations on an eMail base. Only can register for example.

Q2 - Who is impacted?
Passbold is for teams/companies. Therefore would be nice to make it accessible through the web but limit public registrations for safety reason.

Q3 - Why is it important and/or urgent?
It increases the security because this way only users with an email address of the company can sign up. Not anyone else.

Q4 - What is your proposed solution? (optional)
As an admin user I have either the possibility through a GUI to make such settings like sign up limitation or through an ENV var. E.g.

I made a quick patch PR is here Restrict public reg by jsm222 · Pull Request #435 · passbolt/passbolt_api · GitHub