feat: pass FINNHUB_API_KEY to Docker, update layer defaults, cluster APRS

- Add FINNHUB_API_KEY to docker-compose.yml so financial ticker works
  in Docker deployments
- Update default layer config: planes/ships ON, satellites only for
  space, no fire hotspots, military bases + internet outages for infra,
  all SIGINT except HF digital spots
- Add MapLibre native clustering to APRS markers (matches Meshtastic)
  with cluster radius 42, breaks apart at zoom 8

docker-compose.yml

@@ -10,6 +10,7 @@ services:
       - OPENSKY_CLIENT_SECRET=${OPENSKY_CLIENT_SECRET}
       - LTA_ACCOUNT_KEY=${LTA_ACCOUNT_KEY}
       - ADMIN_KEY=${ADMIN_KEY:-}
+      - FINNHUB_API_KEY=${FINNHUB_API_KEY:-}
       # Override allowed CORS origins (comma-separated). Auto-detects LAN IPs if empty.
       - CORS_ORIGINS=${CORS_ORIGINS:-}
       # Default Infonet relay peer so fresh installs can sync immediately.