feat(layers): highlight aircraft broadcasting a transponder emergency

Flights and Military Flights tint aircraft red while the latest poll
carries squawk 7500/7600/7700 or an adsb.lol ADS-B emergency status
(general/unlawful/nordo/downed). Minimum-fuel and lifeguard priorities
are reported but not tinted. The Cockpit HUD aircraft-meta line names
the broadcast code in red. The status is not sticky: a cleared code
stops highlighting on the next refresh.

The analyst/voice query engine gains squawk, emergency and
emergencyKind fields. No new source or request: OpenSky state vectors
already carry the squawk and adsb.lol/readsb carries both fields.

Built by the Hex project (Crew Leo Agile dev team).

Co-Authored-By: Claude <[email protected]>

src/sources/live/aircraft.js

@@ -30,6 +30,9 @@ export function normalizeOpenSkyAircraft(row) {
     typeCode: null,
     registration: null,
     operator: null,
+    squawk: cleanText(row[14]) || null,
+    // State vectors carry no ADS-B emergency field; the squawk stands alone.
+    emergency: null,
   };
 }
 
@@ -68,6 +71,8 @@ export function normalizeReadsbAircraft(row, snapshotTimeMs) {
     typeCode: cleanText(row.t),
     registration: cleanText(row.r),
     operator: cleanText(row.ownOp),
+    squawk: cleanText(row.squawk) || null,
+    emergency: cleanText(row.emergency).toLowerCase() || null,
   };
 }