nz v0.3.1
refactor:
- remove dead code: msgPing/msgPong/msgRouteReport chain (~180 lines)
- remove unused handlePong/handleRouteReport/handlePing/reconnectPeer/reportRoutes
- remove staleReported/peerRoutes fields and related logic
- remove unused routeP2P/routeRelay constants
- route reporting now handled by node reportRoutes via msgRouteReport