Implement transport abstraction (TCP/iroh), announce and routing table,
multi-hop mesh router, truncated-address link layer, and LoRa mock
medium with fragmentation plus EU868-style duty-cycle accounting.
Add mesh_lora_relay_demo and scripts/mesh-demo.sh. Relax CBOR vs JSON
size assertion to match fixed-size cryptographic overhead. Extend
.gitignore for nested targets and node_modules.
Made-with: Cursor
