Bind Elasticsearch to 127.0.0.1 in Zammad install

Explicitly bind Elasticsearch to 127.0.0.1 instead of relying on localhost resolution. Updates elasticsearch.yml, health check curl, and Zammad ES URL setting to use 127.0.0.1 for consistency and to avoid potential IPv6 resolution issues.

install/zammad-install.sh

@@ -32,6 +32,7 @@ sed -i 's/^#\{0,2\} *-Xms[0-9]*g.*/-Xms2g/' /etc/elasticsearch/jvm.options
 sed -i 's/^#\{0,2\} *-Xmx[0-9]*g.*/-Xmx2g/' /etc/elasticsearch/jvm.options
 cat <<EOF >/etc/elasticsearch/elasticsearch.yml
 discovery.type: single-node
+network.host: 127.0.0.1
 xpack.security.enabled: false
 bootstrap.memory_lock: false
 EOF
@@ -40,7 +41,7 @@ systemctl daemon-reload
 systemctl enable -q elasticsearch
 systemctl restart -q elasticsearch
 for i in $(seq 1 30); do
-  if curl -s http://localhost:9200 >/dev/null 2>&1; then
+  if curl -s http://127.0.0.1:9200 >/dev/null 2>&1; then
     break
   fi
   sleep 2
@@ -55,7 +56,7 @@ setup_deb822_repo \
   "$(get_os_info version_id)" \
   "main"
 $STD apt install -y zammad
-$STD zammad run rails r "Setting.set('es_url', 'http://localhost:9200')"
+$STD zammad run rails r "Setting.set('es_url', 'http://127.0.0.1:9200')"
 $STD zammad run rake zammad:searchindex:rebuild
 msg_ok "Installed Zammad"