cmd_promote() changed a user's role with no audit trail, unlike the
identical change from the web Admin Console (set_user_role() ->
log_event(), action "role_changed"). Not a new privilege - anyone
with container-exec access already has DB access directly, D16's own
trust-tier reasoning - but there was no record of who ran it or what
changed.
Now writes an AuditLog row matching set_user_role()'s shape, tagged
via:cli (mirrors JIT provisioning's via:okta_jit) since a container
shell exec carries no signed-in identity to attribute the change to.
Verified against a scratch SQLite db: audit row lands correctly, role
change persists, the no-such-user refusal still exits 1 clean.