classes.RevokeUserAccess stamps users.tokens_valid_after (whole seconds) and
revokes the users' personal API tokens; DeactivateUsers and BanUsers call
it for every selected user. Restore and unban revive nothing, and a
deactivated user who signs in again gets a fresh working token.
POST /refresh now loads the token's subject after bouncer.Refresh and
refuses a missing, deactivated or banned user and a token issued before
tokens_valid_after with the existing 401 body; a refused refresh stamps no
last_seen. Suspension is deliberately not checked.