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/httproute.yaml

@@ -0,0 +1,23 @@
+---
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: vault
+  namespace: vault
+  labels:
+    app.kubernetes.io/name: vault
+    app.kubernetes.io/instance: vault
+spec:
+  hostnames:
+    - vault.k8s.syd1.au.unkin.net
+  parentRefs:
+    - name: vault
+      sectionName: https
+  rules:
+    - backendRefs:
+        - name: vault
+          port: 8200
+      matches:
+        - path:
+            type: PathPrefix
+            value: /