## What changed
- Share the harness runtime identity with analytics delivery and turn-cost queries, and resolve request authentication together with its account-bound transport policy.
- Add runtime authentication to ChatGPT request helpers and `codex cloud`, including environment discovery. Resolve environment credentials for each request and honor CLI configuration overrides when loading cloud authentication.
- Preserve custom-backend authentication, validate runtime destinations, and keep cloud requests from following redirects.
- Forward only organization and project selectors from model-provider headers to API-key analytics requests.
## Testing
Add regression coverage for runtime request signing, credential refresh, account and resource selection, redirect credential handling, custom destinations, and cloud credential-store overrides.
GitOrigin-RevId: 75f33961ee6482881e9ff9817e99d977f31b65b8
