Exclude LXC IPs from link stats collection

Add links_exclude_ips to monitor config; collect() skips any Prometheus
instance whose IP is in that list, preventing LXC containers from
appearing on the links/inspector pages as phantom hosts.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

monitor.py

@@ -553,10 +553,13 @@ class LinkStatsCollector:
         """
         prom_metrics = self._collect_prom_metrics()
         result_hosts: Dict[str, Dict[str, dict]] = {}
+        exclude_ips = set(self.cfg.get('monitor', {}).get('links_exclude_ips', []))
 
         for instance, iface_metrics in prom_metrics.items():
-            host    = instance_map.get(instance, instance.split(':')[0])
             host_ip = instance.split(':')[0]
+            if host_ip in exclude_ips:
+                continue
+            host    = instance_map.get(instance, host_ip)
             ifaces  = list(iface_metrics.keys())
 
             # SSH ethtool collection via Pulse worker — only for explicitly configured