ConnectionMonitor.gather_cluster_stats was calling :rpc.call(Node.self())
which GenServer.call'd back into itself while blocked in handle_info,
causing a 5-second deadlock timeout every 30 seconds. Fixed by computing
local stats directly from state.
LeaderElection never verified that a leader still held the :global
registration. After :global conflict resolution (two isolated nodes
merging), the loser was silently unregistered but stayed is_leader: true
forever, causing both pods to connect to APRS-IS with the same callsign
in a reconnect loop. Fixed by adding verify_leadership/1 to
check_leadership which detects lost registrations and steps down.
