Reframe Briefing into GP-window sections with driver/team tag chips, a sticky
"since last race" header, and client-side digest helpers (gpWindows, groupByWindow,
tagItems). Overlapping inter-race windows resolve to the latest GP; undated items
land in a Recent bucket. Vitest covers digest lib + page render/filter behaviour.
Co-authored-by: Cursor <cursoragent@cursor.com>
