Retrieve a single schedule item (meeting / calendar event) by ID, including AI Notetaker content when available: transcript_text and outline_text (plain text for reading/quoting), plus transcript_json_string and chapters_json_string (raw Notetaker JSON).
When recording_id is present, recording_download_url / recording_download_url_expires_at is a short-lived S3 URL for the audio/video file. Prefer that over schedule_item_recordings_download.
Schedule items are meetings; use this after schedule_items_index filtered by person_id to pull that person's Notetaker transcript.