## What changed
- Rename ChatGPT-specific bundle loaders to `chatgpt_config_bundle_loader*` and use managed-config terminology for shared loader plumbing.
- Pass `Config` directly when updating the app-server's managed configuration loader.
- Share configuration loading, logging setup, and result handling between browser and device-code login.
- Expose the CLI cloud-config helpers and `provider_uses_first_party_auth_path` through their library APIs.
## Testing
Extend CLI login coverage to verify that `forced_login_method="api"` rejects both `login` and `login --device-auth` while preserving saved API-key credentials.
GitOrigin-RevId: 9e8fa6110dc80882ba365e550b48ac77da604940