fix: resolve race condition in entrypoint and simplify ND_DBPATH

entrypoint.sh

@@ -31,6 +31,9 @@ echo "Starting leadership-aware entrypoint..."
 echo "Node IP: $NODE_IP"
 echo "Consul: $CONSUL_HTTP_ADDR"
 
+# Small sleep to let LiteFS settle and leadership election complete
+sleep 5
+
 while true; do
     # In LiteFS 0.5, .primary file exists ONLY on replicas.
     if [ ! -f /data/.primary ]; then