- Introduced new types for endpoint preferences to support 'responses'.
- Added functions to extract safe passthrough headers, Claude-specific headers, and responses-specific headers.
- Implemented logic to ensure proper handling of stream accept headers.
- Updated endpoint resolution logic to prioritize 'responses' in certain contexts.
- Enhanced request building for 'messages' and 'responses' endpoints with improved body sanitization and header management.
- Added comprehensive documentation for new features and usage instructions.