retention is a host concern — agents have no business doing their
own cleanup, and a misbehaving harness could skip it. drop
spawn_events_vacuum from both hive-ag3nt and hive-m1nd, drop the
matching Bus::vacuum + EventStore::vacuum methods. new
hive_c0re::events_vacuum module sweeps every existing
agents/<name>/state/hyperhive-events.sqlite on the same hourly
cadence as the broker vacuum. same two-stage delete (older than 7
days, trim to 2000 newest). called from main alongside broker
vacuum.
also: server-side state badge entered into todo.md (today's badge
is derived client-side from sse, fine for idle/thinking but a
state machine that grows compacting/napping wants authoritative
status from the harness).
