CAIP 19 - agent identifier

[friedger]

The agent identifier should be represented as a chain agnostic asset like

stacks:1/sip009:SP1NMR7MY0TJ1QA7WQBZ6504KC79PZNTRQH4YGFJD.identity-registry-v2.agent-identity/4

Two agents on other chains:

1. Agent #0 on Ethereum mainnet (owner: 0x9ce7082814bda389f3ba548bdf2626006279569c):
   eip155:1/erc721:0x8004A169FB4a3325136EB29fA0ceB6D2e539a432/0
2. Agent #0 on Base mainnet (owner: 0xa1daee3eb47f05f857aca817523f9ff11d95bd71):
   eip155:8453/erc721:0x8004A169FB4a3325136EB29fA0ceB6D2e539a432/0

[whoabuddy]

good call! linking spec to be merged as well for context:
ChainAgnostic/namespaces#167

[whoabuddy]

Closing — CAIP-19 agent identifiers fully implemented in lib/caip19.ts and returned by all agent API endpoints. Shipped in PR #209.