FEAT(repo): add App of Apps self-reference

- Add application.yaml for ArgoCD self-registration
- Update kustomization.yaml to include application.yaml
- Set prune: false to prevent cascade deletion

kustomization.yaml

@@ -2,6 +2,9 @@ apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 
 resources:
+  # Self-reference for App of Apps pattern
+  - application.yaml
+
   - authelia/argocd.yaml
   - vault/argocd.yaml
   - external-secrets/argocd.yaml