Replace user deletion with deactivation

Deactivation adds the alumni role and leaves the others in place, so
reactivation is lossless and nobody has to remember what an account held.
login_from_session checks alumni? on every request, so a signed-in user is
locked out on their next one without any session invalidation. Guards
prevent deactivating yourself or the last active admin, and both verbs are
witnessed in the action log.

0 files changed, 0 insertions, 0 deletions