## 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
## Why
Cloud task requests can use saved ChatGPT credentials, so their destination must be constrained before authentication is loaded or any request is made.
## What changed
- Validate `CODEX_CLOUD_TASKS_BASE_URL` against trusted ChatGPT HTTPS origins on port 443 and reject URLs containing user information, queries, or fragments.
- Disable redirects for cloud task backend and environment-discovery clients so credentials are never forwarded to a redirect destination.
- Normalize the validated base URL before configuring authentication and HTTP clients.
## Testing
Add a CLI integration test that verifies a custom cloud backend is rejected without receiving a request, while the staging origin continues to use explicit token authentication.
GitOrigin-RevId: f0dddf363b4e44ea3530f81d9a817e978c15ead2