Add logviewer.unkin.net internal DNS record (#405)

## Why
logviewer.unkin.net does not resolve, so the log viewer UI is unreachable even though its Gateway and certificate already exist (from #404).

## Changes
- Adds DNSRecord `logviewer-dns-internal` (A, ttl 600 → 198.18.200.4, the internal traefik gateway VIP) to bind-internal authoritative records, mirroring the existing ghp/identity records

Reviewed-on: #405
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

apps/base/bind-internal/authoritative/records.yaml

@@ -117,3 +117,18 @@ spec:
     # traefik-EXTERNAL (DMZ) gateway VIP; the arrproxy Gateway serves the
     # arrstack.unkin.net front door (oauth2-proxy) there.
     - 198.18.199.0
+---
+apiVersion: bind.unkin.net/v1alpha1
+kind: DNSRecord
+metadata:
+  name: logviewer-dns-internal
+  namespace: bind-internal
+spec:
+  zoneRef: unkin-net
+  name: logviewer
+  type: A
+  ttl: 600
+  values:
+    # traefik-internal gateway VIP; the logviewer Gateway serves
+    # logviewer.unkin.net there.
+    - 198.18.200.4