Worldwide airport orientation

Adds a worldwide OurAirports orientation layer with clustered airport points that load only from zoom level 6.
Suppresses OurAirports map points and proximity notices wherever a fresh official national geozone dataset is active.
Adds type-specific airport proximity notices to Risk Assessment and directs pilots to the official national source; SkyMission remains a planning aid, not an authorization service.
Synchronizes the public-domain airport dataset weekly through Synchronize all while excluding closed airports.
Removes the United States, Canada and Germany from planned geozone sources; France remains planned for review after the October source change.

Changelog