Enlarge cluster nodes page container to 95% width

- Change container max-width to 95% for better use of screen space
- Maintain centered layout for the cluster nodes table

templates/admin/cluster_nodes.html

@@ -4,7 +4,7 @@
 
 {% block head %}
 <style>
-    .container { max-width: 1400px; margin: 2rem auto; padding: 0 2rem; }
+    .container { width: 95%; max-width: none; margin: 2rem auto; padding: 0 2rem; }
     .admin-card { background: white; padding: 2rem; border-radius: 12px; box-shadow: 0 2px 10px rgba(0,0,0,0.05); margin-bottom: 2rem; }
     .card-header { margin-bottom: 1.5rem; }
     .card-header h3 { margin: 0; color: #1e293b; }