Every AIS position message walked both the vessel map and the pending-track
map to expire stale entries, and once the store was past its 50,000 cap it
also sorted every row to find the one to evict. The static-data map was never
pruned at all.
The expiry walk now runs on the existing 15 s AIS watchdog tick. Readers
already filtered rows by age; the track reader and the pending first fix now
check age too, so nothing expired is served between ticks. The vessel map is
re-inserted on update, which keeps it least recently updated first, so the
cap is enforced per message by dropping from the front. A vessel's static
entry goes when the vessel does, and static entries that never got a position
are held to the same cap.
Co-Authored-By: Claude Fable 5.2 <[email protected]>
