Freezes an account (data kept, login blocked) gated on the typed Priv::Suspend.
A typed Suspension{by,reason,ts,expires} on the account, folded through the
event log (persists, replays, federates) -- no stringly Extensible/Checker like
Anope. Expiry is evaluated lazily at check-time, so there is no expiry timer.
Blocks IDENTIFY and all SASL mechanisms (via one sasl_login gate); logs out any
live sessions on suspend; the login refusal names who/when/why and when it
lifts. Shown in INFO to owner/auspex. Data + full-flow tests.