3.19.0 (2026-09-22) Features api: add GCP external storage support (#3943) (d12d60f) api: add GPT-Rosalind research model (#3940) (d041d73) Bug Fixes _utils/_transform: propagate __api_exclude__ in _async_transform_recursive (#3324) (161ae65) api: handle omission markers in queued WebSocket events (#3944) (63e4616) client: retry only replayable request content (#3771) (6e0c2be) client: tolerate older optional aiohttp installations (#3941) (0d91efb) helpers: use asyncio.get_running_loop() inside async methods (#3289) (bac3545)