function SyncButton() {
    const { sync, isSyncing, pendingCount, isOnline } = useSyncClient({
        apiUrl: '/api/smartauth',
        getAccessToken: () => localStorage.getItem('access_token'),
        scope: ['thirdparty', 'contact']
    });

    const handleSync = async () => {
        const result = await sync();
        console.log('Synchronisé:', result);
    };

    return (
        <button
            onClick={handleSync}
            disabled={isSyncing || !isOnline || pendingCount === 0}
        >
            {isSyncing ? 'Synchronisation...' : `Synchroniser (${pendingCount})`}
        </button>
    );
}