Quiet sites probed hundreds of thousands of packets to fill a page.
Walk idx_observations_iata_heard per requested site and dedup instead.
Filtered lists now order by site-local recency; the cursor follows.
text[] from string_to_array can't match the CHAR(3) indexes and hides
the values from the planner. Handlers already have a slice; stop
joining to CSV in the store layer and pass a typed array everywhere.