Generate deterministic template headlines server-side for each replay chapter
kind, expose Chapter.headline in the race-hub payload, and render a horizontal
chapter strip on the story view with active-chapter highlighting, click-to-jump,
and a 90-second tour mode built on the existing scrubber playback.
Co-authored-by: Cursor <cursoragent@cursor.com>
Add deterministic server-side chapter detection for starts, flag periods, pit phases, decisive top-five swings, and finishes, then expose chapters on the race-hub payload.
Spike result: race-hub already loads race control, positions, and laps in one read model. The requested Detect signature does not include pit stops, so pit phases use IsPitOutLap clusters as the local deterministic pit-stop proxy.
