chore(timetable): drop unnecessary void on router.replace inside useActiveDay glue

Lint cleanup spotted during Phase C — `router.replace` returns Promise<void>
which the no-void rule rejects. The dropped void had no behavioural effect.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/app/src/pages/events/[id]/timetable/index.vue

@@ -77,7 +77,7 @@ const { activeDayId: dayIdRef, setActiveDay } = useActiveDay({
   queryDay,
   validIds: validSubEventIds,
   replace: id => {
-    void router.replace({ query: { ...route.query, day: id } })
+    router.replace({ query: { ...route.query, day: id } })
   },
 })