feat(vault): deploy HashiCorp Vault 2.0.1 with raft HA (5 replicas)

StatefulSet with templated PVC (cephrbd-fast-delete, 10Gi), headless
service for raft cluster communication, HTTPS gateway (443→8200), and
kubernetes provider retry_join for automatic cluster formation.

apps/base/vault/role.yaml

@@ -0,0 +1,16 @@
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: vault
+  namespace: vault
+  labels:
+    app.kubernetes.io/name: vault
+    app.kubernetes.io/instance: vault
+rules:
+  - apiGroups: [""]
+    resources: ["pods"]
+    verbs: ["get", "list", "watch"]
+  - apiGroups: [""]
+    resources: ["pods"]
+    verbs: ["patch", "update"]