## What changed
Extend `codex-runtime-agent-instance` with a registration client and an in-memory assertion signer. Pending registrations retain their signing key and idempotency key across caller-driven retries; registered runtimes generate fresh versioned assertions with a timestamp and unique ID.
Bound registration requests and responses, reject unsafe endpoints, disable redirects and request logging, and preserve network policy errors. Report server rejections using only the status and recognized error codes.
## Testing
Add HTTP-backed tests for retry stability, assertion signatures and freshness, policy revocation, endpoint and response validation, redirect refusal, and error redaction.
GitOrigin-RevId: a6dab0900459dfb75f72652a0a2ee1e4b65ca322
## What changed
Add `codex-runtime-agent-instance` with serializable registration requests and deserializable responses. Requests support OAuth, personal access tokens, and platform API keys, along with an installation ID, public key, harness metadata, and runtime role. Responses include runtime and host IDs plus ChatGPT or platform actor context.
Use `RedactedString` for credentials to keep secrets out of debug output.
## Testing
Add tests covering request serialization for all three credential types, debug redaction, response decoding for both actor types, and rejection of responses missing required fields.
GitOrigin-RevId: f33bae734fdd1402144dee407e5b868f5eef1d37
cooper-oai