* feat(db): packet type domains, row-cursor indexes and the inverted-heard index
* feat(api): exact page cursors for packets, nodes and observers
* feat(db): normalise packet list filters before choosing a statement
* feat(db): one packets statement per filter shape with an exact row cursor
* fix(db): let the window statements decide since after until
* feat(db): exact keyset cursors for nodes and observers; observers page by last_seen
* feat(api): pageCursor on packets, nodes and observers; it wins over cursor
* test(planguard): packets statements and node/observer keysets leave pending; diff and storediff cases
* chore: bump version to 2.1.0
* test(db): turn off JIT in the keyset cursor tests
Stats endpoints read hourly rollup tables filled once per closed hour by one
advisory-locked task, instead of materialized views that re-scanned every
observation on each refresh. IATA-set tables give exact distinct counts for any
IATA set or region. Cleanup holds raw rows for unrolled hours (up to 24h).
Adds /stats/series; ingest keeps packet observation counts, observer last IATA,
channel message counts and trace tag summaries. 001_baseline.sql is rewritten,
so pre-release 2.0 databases must be recreated. See docs/historical-stats.md.
MrAlders0n