feat(admin): add manual R2 stats refresh endpoint/button and share in-memory storage snapshot cache

components/admin/refresh-r2-stats-button.tsx

@@ -0,0 +1,50 @@
+'use client';
+
+import { useState } from 'react';
+import { useRouter } from 'next/navigation';
+import { Loader2, RefreshCw } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+
+export function RefreshR2StatsButton() {
+  const router = useRouter();
+  const [isRefreshing, setIsRefreshing] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const handleRefresh = async () => {
+    setIsRefreshing(true);
+    setError(null);
+
+    try {
+      const response = await fetch('/api/admin/stats/refresh-r2', {
+        method: 'POST',
+      });
+
+      const payload = await response.json().catch(() => ({}));
+      if (!response.ok) {
+        const message = (payload as { error?: string }).error || 'Failed to refresh R2 stats';
+        setError(message);
+        return;
+      }
+
+      router.refresh();
+    } catch {
+      setError('Failed to refresh R2 stats');
+    } finally {
+      setIsRefreshing(false);
+    }
+  };
+
+  return (
+    <div className="flex flex-col items-end gap-1">
+      <Button type="button" variant="outline" size="sm" onClick={handleRefresh} disabled={isRefreshing}>
+        {isRefreshing ? (
+          <Loader2 className="mr-1.5 h-4 w-4 animate-spin" />
+        ) : (
+          <RefreshCw className="mr-1.5 h-4 w-4" />
+        )}
+        {isRefreshing ? 'Refreshing...' : 'Refresh R2 Stats'}
+      </Button>
+      {error ? <p className="text-xs text-destructive">{error}</p> : null}
+    </div>
+  );
+}