Create a new account manually on self-hosted, without allowing subscriptions

I can't figure out upon quick perusal of the documents whether one can create a new account manually, without opening up public subscriptions. Command line would be fine, GUI would be nice.

Use case: Small self-hosted instance for family/friends to use, WITHOUT sharing all the contacts in one's personal account. I see how one can invite a new "user" to an "account", but that's not what I'm talking about. I don't want to have to police a public instance constantly for potential spam subscription requests, when I know exactly the small number of people I want to have access to it.

The feature request currently open, to add an admin panel, might make this request redundant, in which case I'll wait for that work to be finished.