fix(argocd): enable kustomize helm chart support

Add kustomize.buildOptions: --enable-helm to argocd-cm so that
kustomization.yaml files using helmCharts: can be built correctly.
Required for the Loki HelmChart in infrastructure/base/monitoring.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: soohyunme

infrastructure/overlays/prod/argocd/values.yaml

@@ -5,6 +5,7 @@ configs:
   cm:
     url: https://argocd.pseudolab-devfactory.com
     users.anonymous.enabled: "false"
+    kustomize.buildOptions: --enable-helm
     # Shared account for bingo service admins (set password in argocd-secret)
     accounts.bingo-admin: login
   rbac: