Clamp active-chapter detection to the same scrub bounds as chapter clicks,
keep an explicit selection on click for out-of-window timestamps, point E2E
at the empty-state card, and move Race Story empty-state styles out of app.css.
Co-authored-by: Cursor <cursoragent@cursor.com>
Consolidate the Race Story section into a cohesive timeline surface: custom
chapter-strip scrolling with active-card sync, unified segmented playback
controls, chapter bands on the position graph with decimated axes and
de-collided labels, map toggle gated by an on-mount replay/outline probe,
and shared empty-state cards. Adds vitest coverage and visual snapshots.
Note: replay/outline queries now probe on mount (not only when Map opens) so
the toggle can be hidden before users hit a dead panel.
Co-authored-by: Cursor <cursoragent@cursor.com>
