[FEATURE] allow disabling users and account creation at server start

[hello-woof]

Description

I don't need any user accounts or user creation requirements, so I would just like to have it disabled by default when the server starts instead of having to log in as the root user to change it.

Screenshots

No response

Additional information

Today I just fork Hemmelig.app and put the following into server/adminSettings.js

adminSettings.set("disable_users", true);
adminSettings.set("disable_user_account_creation", true);

It would be nice to configure this from env variables.

[bjarneo]

Good thought. Can easily be done using env vars on runtime!