feat(consul): address PR review feedback

- Fix consul HTTPRoute backend: consul-consul-ui -> consul-ui
- Add consul.service.consul hostname to Gateway (cert SAN) and HTTPRoute
- Add consul-svc listener on 443 for consul.service.consul SNI routing
- Convert PDB inline patch to patches/consul-server-pdb.yaml
- Set server.disruptionBudget.maxUnavailable: 1 explicitly in values
- Expose consul DNS service as LoadBalancer (purelb 198.18.200.5) for anycast
- Remove sandbox overlay (not needed in production GitOps)

apps/overlays/au-syd1/consul/kustomization.yaml

@@ -6,13 +6,10 @@ resources:
   - ../../../base/consul
 
 patches:
-  - target:
+  - path: patches/consul-server-pdb.yaml
+    target:
       kind: PodDisruptionBudget
       name: consul-server
-    patch: |-
-      - op: replace
-        path: /apiVersion
-        value: policy/v1
 
 helmCharts:
   - name: consul