fix(dashboard): keep the legacy hero rendering as before

Revert the Today-hero-owns-the-slot suppression from this branch: the legacy
opt-in dashboard hero is asserted by the mobile-density and dashboard e2e
landmarks, and retiring it cleanly (with its settings toggle and those specs)
is a separate change. For now both heroes render exactly as before this branch;
the default account (legacy hero off) still shows only the Today hero.

src/app/page-client.tsx

@@ -799,12 +799,7 @@ export default function DashboardPageClient() {
           <TodayHero digest={digestQuery.data} />
         ) : null)}
 
-      {/* The digest-driven TodayHero owns the promoted hero slot whenever
-          Insights is on (Marc sign-off, decision 1). The legacy opt-in
-          DashboardHero only shows for an Insights-disabled account, so the two
-          heroes never stack. */}
       {heroVisible &&
-        !insightsEnabled &&
         (primaryLoading || !heroSnapshot ? (
           <DashboardHeroSkeleton />
         ) : (