Say how ArgoCD is really bootstrapped on GKE

The header claimed a manual helm install of argocd-admin-prd; Terraform
installs it, as release argo-cd, before the Application takes over.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Fn2kUxyYNY4ApytbLiGWeY

helm-overrides/gke-toolshed-prd-usc1/argocd-admin-prd/custom-values.yaml

@@ -2,9 +2,12 @@ argo-cd:
   # GKE counterpart of the homelab's argocd-admin-prd override
   # (k8s-admin-prd-ase1, in the homelab devops-infra-helm-charts repo).
   #
-  # Installed once by hand with `helm install argocd-admin-prd` (namespace
-  # "argocd"), then manages itself through the argocd Application in
-  # devops-infra-argo-config-gcp, whose nameOverride matches that release.
+  # Bootstrapped by Terraform, not by hand: toolshed-gke-infra's
+  # envs/prod/20-bootstrap/argocd.tf installs the upstream argo-cd chart
+  # directly (release "argo-cd", namespace "argocd") with its own inline
+  # values. After that, ArgoCD manages itself through the argocd Application
+  # in devops-infra-argo-config-gcp (nameOverride "argocd-admin-prd"), which
+  # renders this wrapper chart with the values in this file.
   # Deliberately no image tag pin, unlike the homelab: the chart's own
   # appVersion (v3.5.2) governs, so the image cannot drift from the chart.
   # A pin that outlives its chart is close to the failure this upgrade