feat(#76): bound primary-route fetches and local-first driver summary

Add shared apiFetch timeouts/abort/typed errors with in-flight dedupe, a
RouteState UI for loading/empty/timeout/error+retry, and wire it through
Weekend (Data Health), Championship, Driver Profile, Briefing, Live, and
Race Hub. Driver summary is local-first with bounded optional OpenF1
enrichment so a hung remote call cannot block the profile.

Spike note: parseSourceMode defaults to openf1; driver summary now treats
omitted ?source= as auto so local season data is preferred.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/pages/RacePreviewPage.tsx

@@ -271,7 +271,7 @@ export function RacePreviewPage() {
 
   const seasonsQuery = useQuery({
     queryKey: ['seasons'],
-    queryFn: fetchSeasons,
+    queryFn: ({ signal }) => fetchSeasons(signal),
   })
 
   const latestSeason = seasonsQuery.data?.[0] ?? null