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>

config.json

@@ -31,7 +31,8 @@
     "poll_interval": 300,
     "failure_threshold": 2,
     "cluster_threshold": 3,
-    "ping_hosts": []
+    "ping_hosts": [],
+    "links_exclude_ips": ["10.10.10.29", "10.10.10.44", "10.10.10.3"]
   },
   "hosts": [
     {