GKE: register Contour as an Application

Contour is installed by ArgoCD rather than by hand, which is only
possible because nothing in the bootstrap path needed an ingress:
ArgoCD reaches Gitea over cluster DNS. Its HTTPProxy CRD embeds a large
schema, so the entry uses ServerSideApply for the same reason
cert-manager's does.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LEsTefWWifp4ikvhHF5s6N

values/incubator-infra-gke-toolshed-prd-usc1-values.yaml

@@ -39,6 +39,18 @@ appSpec:
     namespace: gitea
     chartDir: gitea
     valuesDir: gitea
+  - name: contour
+    # The cluster's only inbound path, pinned to the reserved IP that every
+    # nip.io hostname is built from. Installed by ArgoCD rather than by
+    # hand, which is only possible because nothing in the bootstrap needed
+    # an ingress: ArgoCD reaches Gitea over cluster DNS.
+    nameOverride: contour
+    namespace: projectcontour
+    chartDir: contour
+    valuesDir: contour
+    # Contour's HTTPProxy CRD embeds a large schema, same 256KiB
+    # last-applied-configuration problem as cert-manager's.
+    serverSideApply: true
   - name: cert-manager
     nameOverride: cert-manager
     namespace: cert-manager