Prepare railiance01 delivery: dynamic leases, migrate Job, operator runbook

VaultDynamicSecret pulls database/creds/* so a rotating lease is not frozen
into KV. Runtime sets AUDIT_CORE_AUTO_MIGRATE=0; schema is a Job with the
migration lease. Image base is digest-pinned. Namespace and NetworkPolicies
are on the cluster; Deployment waits for the attended OpenBao ESO token.

deploy/clustersecretstore.yaml

@@ -0,0 +1,31 @@
+# Template of the railiance-platform add-on store. Prefer applying from:
+#   ~/railiance-platform/argocd/platform-addons/openbao-secretstore/openbao-audit-core.clustersecretstore.yaml
+#
+# Do not apply until Secret external-secrets/openbao-audit-core-eso-token exists
+# (scripts/openbao-eso-token-apply.sh). This store is KV-only: sender registry
+# lives at platform/workloads/audit-core/senders. Database leases are dynamic
+# and come from VaultDynamicSecret, not this store.
+---
+apiVersion: external-secrets.io/v1
+kind: ClusterSecretStore
+metadata:
+  name: openbao-audit-core
+  labels:
+    app.kubernetes.io/part-of: railiance-gitops
+    railiance-platform/component: external-secrets
+    app.kubernetes.io/name: audit-core
+spec:
+  provider:
+    vault:
+      # In-cluster OpenBao on railiance01, not the public bao.coulomb.social UI.
+      server: http://openbao.openbao.svc:8200
+      path: platform
+      version: v2
+      auth:
+        tokenSecretRef:
+          name: openbao-audit-core-eso-token
+          namespace: external-secrets
+          key: token
+  conditions:
+    - namespaces:
+        - audit-core