geofencesToMonitor
fun Collection<DataPacket>.geofencesToMonitor(myNodeNum: Int?, optedInIds: Set<Int>): List<Waypoint>(source)
The geofences whose crossings THIS device should raise notifications for: waypoints we created (isFromLocal) plus any the user has explicitly opted into (optedInIds). Foreign geofences are excluded by default because waypoints are mesh-broadcast — every receiver stores them, so without this gate everyone in range would alert on the creator's crossings. Only waypoints that actually request crossing notifications (notifiesOnCrossing) survive.