- Rename NAT types: OPEN->EIM, RESTRICTED->STRICT across all code
- Add flat addr list {type,ip,port,socket_id} to NODEINFO (NODEINFO_IPV4_ADDR)
- Add NODEINFO_IPV4_SOCKET_META for per-socket metadata
- Add NODE_CONNECTIVITY with per-type probe status and min_rtt
- New module: route_connectivity.c/h (probing engine with socket fallback)
- STRICT verified addresses excluded from NODEINFO broadcast
- Trigger probing on new/updated BGP node, cancel on remove/withdraw
- Update NAT type names in etcpmon GUI