- Added support for lifecycle event messages, including a new event type for tracking stream states (e.g., stream_start, stream_end).
- Introduced a NewEventMessage function to create event messages with structured properties.
- Updated the output package to include event messages in the built-in types, ensuring compatibility with CUI clients while remaining silent for OpenAI clients.
- Enhanced the DefaultStreamHandler to utilize event messages for better lifecycle tracking during streaming operations.
- Improved error handling and logging in the OpenAI provider to capture and report streaming errors effectively.