ERC-8004 Validation Registry integration

[lthibault]

Execution traces from chess games can be submitted to the Validation Registry. A third-party validator re-runs the WASM state machine with recorded inputs and confirms the trace matches. Leverages content-addressed images: validator runs ww run /ipfs/QmSameCID with the trace.

Acceptance criteria

• Validator can independently verify a game from trace CID + program CID
• Verification result is recorded on-chain