Add a three-node NATS JetStream cluster on distinct Proxmox LXC guests.

LXC 511–513 (nats-a/b/c on 10.10.10.21–23, vmbr1 only) form cluster
verae with replicas=3. Host loopback 127.0.0.1:4222 is unchanged.

packages/verae-nats-cluster/scripts/status.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+# shellcheck disable=SC1091
+. "$ROOT/cluster.env"
+export PATH="/usr/sbin:/usr/bin:/bin:$PATH"
+printf '%s\n' "$NODES" | awk 'NF==3 {print}' | while read -r vmid name ip; do
+  st="$(sudo pct status "$vmid" 2>/dev/null || echo missing)"
+  js="$(sudo pct exec "$vmid" -- curl -fsS --max-time 2 http://127.0.0.1:8222/varz 2>/dev/null || echo '{}')"
+  echo "$vmid $name $ip $st"
+  python3 -c "
+import json,sys
+try:
+  d=json.loads(sys.argv[1])
+except Exception:
+  print('  nats down')
+  raise SystemExit
+print('  server_name', d.get('server_name'), 'cluster', (d.get('cluster') or {}).get('name'), 'routes', len((d.get('cluster') or {}).get('urls') or d.get('connect_urls') or []))
+print('  jetstream', bool(d.get('jetstream')), 'port', d.get('port'), 'host', d.get('host'))
+" "$js" 2>/dev/null || echo "  nats down"
+done
+echo "host loopback still: $(ss -lnt | grep '127.0.0.1:4222' && echo up || echo down)"