C2(migrate-immich-to-ringtail): impl add cloudnative-pg-ringtail ArgoCD app

Sibling of cloudnative-pg.yaml targeting k3s-ringtail. Same mirror
(mirrors/cloudnative-pg) and release (v1.27.1), same sync options.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

argocd/apps/cloudnative-pg-ringtail.yaml

@@ -0,0 +1,27 @@
+# CloudNativePG Operator for ringtail k3s cluster
+# Deploys the operator only; PostgreSQL clusters are created separately
+#
+# Sibling of cloudnative-pg.yaml (minikube). Same mirror, same release,
+# different destination. Both apps will coexist during the immich
+# migration; the minikube one is removed at the end of the broader
+# indri-k8s decommission.
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: cloudnative-pg-ringtail
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: ssh://forgejo@forge.ops.eblu.me:2222/mirrors/cloudnative-pg.git
+    targetRevision: v1.27.1
+    path: releases
+    directory:
+      include: 'cnpg-1.27.1.yaml'
+  destination:
+    server: https://ringtail.tail8d86e.ts.net:6443
+    namespace: cnpg-system
+  syncPolicy:
+    syncOptions:
+      - CreateNamespace=true
+      - ServerSideApply=true  # Required for large CRDs that exceed annotation size limit