fix(cluster): ensure AstDB transactional sync, auto-healing, and Gratuitous ARP on master take-over

install.sh

@@ -65,7 +65,7 @@ apt-get install -y --no-install-recommends \
     sshpass
 
 # Composants optionnels Haute Disponibilité (Cluster HA)
-apt-get install -y --no-install-recommends keepalived 2>/dev/null || true
+apt-get install -y --no-install-recommends keepalived iputils-arping 2>/dev/null || true
 systemctl stop keepalived >/dev/null 2>&1 || true
 systemctl disable keepalived >/dev/null 2>&1 || true