fix: correct pve1 IP to 10.42.0.4, rename stale joel/opnsense refs

pve1 is a static/DHCP-reserved Proxmox host at 10.42.0.4 (previously
mislabeled 'joel' in some places). 10.42.1.1 is the UDM Pro gateway
IP, not pve1 -- OPNsense was retired in favor of Ubiquiti. Removes
the stale duplicate PVE1 DHCP reservation at 10.42.1.1 and drops the
now-redundant 'joel' entry from network.json (consolidated into
pve1).

manifests/monitoring/config.yaml

@@ -51,8 +51,8 @@ data:
         static_configs:
           - targets:
               - "10.42.0.3"    # OpenWRT access point
-              - "10.42.0.4"    # Joel (Proxmox)
-              - "10.42.1.1"    # pve1 (Proxmox)
+              - "10.42.0.4"    # pve1 (Proxmox)
+              - "10.42.1.1"    # UDM gateway (Ubiquiti)
               - "10.42.1.4"    # chronicles (Synology NAS)
               - "10.42.1.14"   # nas1 (TrueNAS)
               - "10.42.2.57"   # odoo