Add Iroh protocol router scaffold

AGENTS.md

@@ -104,7 +104,7 @@ Roadmap items should be actionable and checkable:
 - Local daemon, local control socket, local identity, local store, local CAS,
   daemon-owned Iroh endpoint startup, built-in relay-mode config, SSH
   certificate metadata, revocation metadata, user service definitions, and a
-  pinned `geth-iroh` endpoint wrapper exist.
+  pinned `geth-iroh` endpoint wrapper with protocol-router scaffold exist.
 - Custom relay maps, mDNS discovery, peer auth over Iroh, cr-sqlite, iroh-docs,
   iroh-gossip, iroh-blobs, Automerge sync, real auth enforcement, OpenSSH KRL
   generation, and Keyhive/BeeKEM-style authorization are future roadmap items