## Why
GitHub Actions workflows can use short-lived OpenAI credentials instead of storing a long-lived OpenAI API key in GitHub secrets.
## What changed
- Add `--github-oidc` with required audience, identity provider, service account, and GitHub token-request URL settings. Read the GitHub request credential from stdin and connect it to the existing federated authentication flow.
- Require the default OpenAI Responses endpoint in OIDC mode before reading credentials, and complete the initial token exchange before publishing server info.
- Close the npm launcher's copy of stdin after the native child starts.
- Document OIDC setup, credential handling, renewal behavior, and caller responsibilities. Keep API-key authentication as the default.
## Testing
Add tests for required OIDC flags, upstream restrictions before credential reads, rejection of unsafe or empty settings without exposing sensitive input, and failure when a configured custom CA cannot be loaded in the CLI blocking context.
GitOrigin-RevId: 7de6fd4c3491e7ccd6a2c2ccdee0bc2eedd0e642