GKE: app registry and bootstrap Application for gke-toolshed-prd-usc1

Adds the GCP counterpart of the homelab's cluster entry point, alongside
it rather than replacing it, so the two clusters never share a values
file:

- values/incubator-infra-gke-toolshed-prd-usc1-values.yaml, starting with
  only argocd, gitea and cert-manager. Every appSpec entry's nameOverride
  equals the Helm release name each is installed under by hand, which is
  what makes ArgoCD adopt those releases instead of rendering a second
  copy of each.
- incubator/incubator-infra-gke-toolshed-prd-usc1.yaml, the parent
  Application, applied once by hand.
- app-of-projects.yaml and the devops AppProject now point at this
  cluster's Gitea over cluster DNS, not the homelab's LAN hostname.

Sources are reached at gitea-http.gitea.svc.cluster.local:3000 rather
than through an Ingress: ArgoCD has to read them before Contour exists,
since Contour is itself one of the Applications it installs.

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

projects/devops-project.yaml

@@ -3,13 +3,12 @@ kind: AppProject
 metadata:
   name: devops
   # Single ArgoCD instance — projects live in the same namespace as
-  # ArgoCD itself (see the argocd/argocd-admin note in
-  # values/incubator-infra-k8s-admin-prd-ase1-values.yaml).
+  # ArgoCD itself (see values/incubator-infra-gke-toolshed-prd-usc1-values.yaml).
   namespace: argocd
   finalizers:
     - resources-finalizer.argocd.argoproj.io
 spec:
-  description: "devops project for infra apps on the homelab VM (team: devops in the appSpec labels)."
+  description: "devops project for infra apps on the GKE cluster (team: devops in the appSpec labels)."
   sourceRepos:
   - '*'
   destinations: