FEAT(cert-manager): integrate cert-manager, Vault, Velero

- Add cert-manager configuration
- Add Vault and Velero integration

vault/kustomization.yaml

@@ -2,13 +2,5 @@ apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 
 resources:
-  # argocd.yaml files은 수동으로 관리 (순환 참조 방지)
-  # - argocd-vault.yaml
-  # - argocd-secrets.yaml
   - namespace.yaml
-
-  # External Secrets integration
-  # ServiceAccount is managed by external-secrets Helm chart
-  - cluster-secret-store.yaml
-  - vault-postgres-secret.yaml
-  # vault-config-job.yaml은 삭제됨 (민감한 정보 포함으로 인해 .md 파일로 대체)
+  - cluster-secret-store.yaml