Configure Lighthouse NAT for Improved Peer Connectivity

Lighthouse uses UDP port 9000 for discovery and TCP 9000 plus UDP 9001 for libp2p data transfer. Proper NAT configuration, including port forwarding and SNAT rules, improves peer connectivity. Default target-peers is 100 with 10% extra for pruning every 30 seconds. Nodes behind CGNAT cannot port forward without ISP help, limiting incoming connections and network efficiency.