Merge current main and reviewed GNSS into import integration

CHANGELOG.md

@@ -24,6 +24,9 @@
   the five borough cores load and `CCTV_NYC_MAX_SOURCES` changes the cap. The catalog-wide ceiling is
   unchanged; extra cameras share it round-robin with the other packs.
 
+- Street Level counts unique tiles before ranking so overlapping dateline halves
+  in polar views do not waste slots in the 16-tile overview budget.
+
 - Directions no longer shows a truncation notice for a route with exactly 200
   turns, and a roundabout at the 200th turn keeps its exit distance.
 
@@ -33,6 +36,19 @@
 
 - Director timeline seeks cross the dateline along the short longitude arc.
 
+- Map state updates stop delivering to subscribers removed during the same notification.
+
+- Director assets cancelled during the final stream read are discarded with reader cleanup.
+
+- Analyst queries preserve useful rows when an upstream timestamp is outside the supported date range.
+
+- Fire detections with missing or impossible positions are skipped while genuine zero coordinates remain valid.
+
+- Frequently reused terrain batches retain their cached heights ahead of unused cells.
+
+- Recent Imagery’s exported `setBox` and `searchHls` reject missing, blank or
+  boolean programmatic box edges instead of interpreting them as zero coordinates.
+
 - Treat explicitly current, complete empty vessel coverage as a successful update,
   clearing obsolete contacts while retaining stale or incomplete snapshots.
 
@@ -128,6 +144,16 @@
 
 ## [Unreleased]
 
+- Flights and Military Flights highlight emergency transponder broadcasts in
+  fleet billboards, 3D models and Cockpit contacts. Colors update when a status
+  starts or clears. Emergency squawks outrank ADS-B priority statuses; GEV
+  reports minimum fuel and lifeguard without red tint. Cockpit names the code
+  or ADS-B status, and analyst/voice results retain broadcast provenance and
+  the latest known contact time. One omitted ADS-B status poll during a source
+  switch may retain the previous status if the squawk is unchanged; an explicit
+  clear takes effect immediately. Broadcasts are not confirmed incidents.
+  Contributed by [Leo Pechnicki](https://github.com/leopechnicki) (#856).
+
 - Street Level: KartaView is the third provider, keyless. Light its chip
   (purple; off by default, one provider at a time) and zoom in below about
   6 km: the lines are the streets KartaView has photos of (z13–14 tiles from
@@ -220,6 +246,17 @@
   File bytes stay on the device; rendered overlays may appear in shared map
   screenshots. Thanks to [Chase Mills](https://github.com/kapturner) (#925).
 
+- GNSS Integrity (Events, voice-addressable, share token `3`) draws navigation
+  accuracy scores from a keyless regional adsb.lol sample; aircraft-level analyst
+  queries are unavailable for these aggregate cells. Cells do not intercept
+  map clicks. Pan/zoom refreshes automatically; feed failures retain the display
+  and explain the next retry. Aircraft-reported quality includes MLAT-positioned
+  contacts after GPS loss, excludes TIS-B/MLAT-derived quality, and locates GPS-loss
+  evidence at the last good GNSS position when available. Scores discount one
+  bad aircraft per cell and retain 30 minutes of visited-view evidence; they
+  do not confirm jamming. See [method and limits](DATA_SOURCES.md#gnss-integrity).
+  Contributed by [Leo Pechnicki](https://github.com/leopechnicki) (#855).
+
 - Live HLS cameras play on a page opened over plain HTTP from another machine
   (`HOST=0.0.0.0`). The client lease id came from `crypto.randomUUID`, which
   browsers only expose in secure contexts, so starting a live feed threw