Add 5-second auto-refresh for dashboard Activity feed

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/(admin)/admin/dashboard-content.tsx

@@ -121,6 +121,10 @@ export function DashboardContent({ editionId, sessionName }: DashboardContentPro
     { editionId, limit: 8 },
     { enabled: !!editionId, refetchInterval: 30_000 }
   )
+  const { data: liveActivity } = trpc.dashboard.getRecentActivity.useQuery(
+    { limit: 8 },
+    { enabled: !!editionId, refetchInterval: 5_000 }
+  )
 
   if (isLoading) {
     return <DashboardSkeleton />
@@ -268,7 +272,7 @@ export function DashboardContent({ editionId, sessionName }: DashboardContentPro
           </AnimatedCard>
 
           <AnimatedCard index={6}>
-            <ActivityFeed activity={recentActivity} />
+            <ActivityFeed activity={liveActivity ?? recentActivity} />
           </AnimatedCard>
         </div>
       </div>