## What changed
- Add the experimental `amazonBedrockAccessKeys` app-server login flow, persist its credentials in the configured auth store, and use them for SigV4-signed Bedrock requests.
- Report `bedrockAccessKeys` as a distinct auth mode and document access-key login alongside AWS profile and environment credential setup.
- Clear the selected Bedrock provider, AWS settings, and Bedrock-specific model on logout while leaving external AWS credentials and `.env` untouched.
- Reject managed access-key login when higher-precedence configuration would prevent its region or profile settings from taking effect.
## Testing
- Cover access-key login, storage, request signing, configuration conflicts, status reporting, and logout cleanup.
GitOrigin-RevId: bbf297887c6503d3651ceb2aad85c4d626e32723