- Add openid to OAuth scopes for id_token issuance
- Preserve id_token, scope, and token_type on token exchange and refresh
- Atomically write and sync .gemini/oauth_creds.json in profile directories
- Auto-resolve active profile environment in discover_models
- Cache discovered models in models_cache.json with graceful timeout handling
- Add unit test coverage for full OAuth lifecycle and model discovery caching
