activity_summaries added for streaming progress; intermediate_outputs deprecated

Set include to ["activity_summaries"] with stream: true to receive live progress summaries as jockey:activity events. Each snapshot contains an activity ID, revision, status, and summary. Activity summaries are delivered only in the stream and are not included in the final response's output or saved message history.

intermediate_outputs is deprecated. Its existing streaming and non-streaming behavior is preserved, including intermediate messages, function calls, and function-call results in output. For progress displays, migrate to activity_summaries and handle jockey:activity events. The two include options cannot be combined.

See Show activity summaries for examples and the Create a response API reference for request options.