Point KeaSubnet DNS at the in-cluster bind-resolvers

DHCP clients should resolve via the k8s bind-resolvers cluster (PureLB 198.18.200.7), not the legacy 198.18.19.15 forwarder.

- Set dnsServers to 198.18.200.7 on all five KeaSubnets.

Claude-Session: https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT

apps/base/dhcp-system/cr/keasubnets.yaml

@@ -1,7 +1,8 @@
 # Translation of the legacy ISC dhcpd pools (puppet
 # roles/infra/dhcp/server.yaml): 198.18.13-17.0/24, each a .200-.220 pool,
-# dns 198.18.19.15, next-server 198.18.19.19. Gateways per the original config:
+# next-server 198.18.19.19. Gateways per the original config:
-# .13/.14/.15/.16 -> .254, .17 -> .1.
+# .13/.14/.15/.16 -> .254, .17 -> .1. DNS points at the in-cluster
+# bind-resolvers PureLB IP (198.18.200.7), not the legacy 198.18.19.15.
 ---
 apiVersion: kea.unkin.net/v1alpha1
 kind: KeaSubnet
@@ -16,7 +17,7 @@ spec:
   pools:
     - 198.18.13.200 - 198.18.13.220
   routers: [198.18.13.254]
-  dnsServers: [198.18.19.15]
+  dnsServers: [198.18.200.7]
   domainName: main.unkin.net
   nextServer: 198.18.19.19
 ---
@@ -33,7 +34,7 @@ spec:
   pools:
     - 198.18.14.200 - 198.18.14.220
   routers: [198.18.14.254]
-  dnsServers: [198.18.19.15]
+  dnsServers: [198.18.200.7]
   domainName: main.unkin.net
   nextServer: 198.18.19.19
 ---
@@ -50,7 +51,7 @@ spec:
   pools:
     - 198.18.15.200 - 198.18.15.220
   routers: [198.18.15.254]
-  dnsServers: [198.18.19.15]
+  dnsServers: [198.18.200.7]
   domainName: main.unkin.net
   nextServer: 198.18.19.19
 ---
@@ -67,7 +68,7 @@ spec:
   pools:
     - 198.18.16.200 - 198.18.16.220
   routers: [198.18.16.254]
-  dnsServers: [198.18.19.15]
+  dnsServers: [198.18.200.7]
   domainName: main.unkin.net
   nextServer: 198.18.19.19
 ---
@@ -84,6 +85,6 @@ spec:
   pools:
     - 198.18.17.200 - 198.18.17.220
   routers: [198.18.17.1]
-  dnsServers: [198.18.19.15]
+  dnsServers: [198.18.200.7]
   domainName: main.unkin.net
   nextServer: 198.18.19.19