Worked on enhancing the reliability of real-time streaming in the pydantic-ai repository by addressing a critical bug in the asynchronous _stream_text_deltas function. Implemented an asynchronous cleanup path to gracefully handle client disconnects, preventing StopAsyncIteration errors and ensuring proper resource release. This change improved the stability of delta delivery during intermittent client connections, reducing runtime failures and support incidents. Utilized advanced Python features, including asynchronous programming and unit testing, to ensure robust and maintainable code. The update contributed to increased uptime and user trust in live text streaming, reflecting a thoughtful approach to error handling and resource management.