Fix two stale hub.mjs lock_events comments: the 317-rows figure and the :930 KPI-view claim

Found during the OPS-257 gate, non-blocking, deliberately kept out of that diff to preserve its md5 chain of custody. (1) The comment beside the lock_events reader states "lock_events is 317 rows all-time" - measured 1025 on the live DB 2026-09-12, and that figure is the stated justification for adding no index, so it will be quoted back at somebody. (2) The comment at :930 claims a KPI view reads lock_events - disproved: SELECT name FROM sqlite_master WHERE type=view AND sql LIKE %lock_events% returns ZERO rows on the live DB. Neither touches behaviour. Fold both into the next hub patch that touches that region; do not spend a deploy on them alone. Evidence: /data-venus/llmmsg-srv/diffs/2026-09-12-ops-257-PM-GATE-VERDICT.md