Renumber gw-cnx-1 to the fleet addressing scheme (OPNsense replacement)

The newedge.house site adopts the 10.1.<vlanId>.0/24 convention: mgmt 10
(the old untagged LAN), lan 20, iot 40, voip 50, dmz 60, unit1-5 110-150.
PPPoE is untagged at this site. Static leases move to a new per-VLAN
dhcp.reservations option rendered into Kea host reservations.

modules/router/dns-dhcp.nix

@@ -29,6 +29,11 @@ in
           interface = "vlan-${name}";
           valid-lifetime = vlan.dhcp.leaseTime;
           pools = [ { pool = "${vlan.dhcp.pool.from} - ${vlan.dhcp.pool.to}"; } ];
+          reservations = lib.mapAttrsToList (host: res: {
+            hostname = host;
+            hw-address = res.hwAddress;
+            ip-address = res.ipAddress;
+          }) vlan.dhcp.reservations;
           option-data = [
             {
               name = "routers";