Auto-refresh jury dashboard every 30s for live round updates

Add AutoRefresh client component that calls router.refresh() on an
interval. Pauses when tab is hidden and refreshes immediately when
tab becomes visible again. Jury dashboard now reflects round
activations within seconds.

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

src/app/(jury)/jury/page.tsx

@@ -3,6 +3,7 @@ import { Suspense } from 'react'
 import Link from 'next/link'
 import { auth } from '@/lib/auth'
 import { prisma } from '@/lib/prisma'
+import { AutoRefresh } from '@/components/shared/auto-refresh'
 
 export const metadata: Metadata = { title: 'Jury Dashboard' }
 export const dynamic = 'force-dynamic'
@@ -744,6 +745,9 @@ export default async function JuryDashboardPage() {
       <Suspense fallback={<DashboardSkeleton />}>
         <JuryDashboardContent />
       </Suspense>
+
+      {/* Auto-refresh every 30s so voting round changes appear promptly */}
+      <AutoRefresh intervalMs={30_000} />
     </div>
   )
 }

src/components/shared/auto-refresh.tsx

@@ -0,0 +1,42 @@
+'use client'
+
+import { useEffect } from 'react'
+import { useRouter } from 'next/navigation'
+
+/**
+ * Invisible client component that periodically calls router.refresh()
+ * to re-fetch server component data without a full page reload.
+ * Pauses when the tab is hidden to avoid unnecessary requests.
+ */
+export function AutoRefresh({ intervalMs = 30_000 }: { intervalMs?: number }) {
+  const router = useRouter()
+
+  useEffect(() => {
+    let timer: ReturnType<typeof setInterval>
+
+    function start() {
+      timer = setInterval(() => {
+        router.refresh()
+      }, intervalMs)
+    }
+
+    function handleVisibility() {
+      clearInterval(timer)
+      if (document.visibilityState === 'visible') {
+        // Refresh immediately when tab becomes visible again
+        router.refresh()
+        start()
+      }
+    }
+
+    start()
+    document.addEventListener('visibilitychange', handleVisibility)
+
+    return () => {
+      clearInterval(timer)
+      document.removeEventListener('visibilitychange', handleVisibility)
+    }
+  }, [router, intervalMs])
+
+  return null
+}