feat(kanidm): vault-managed replication certs with auto-restart (#176)

- Store per-pod replication certs in Vault (kv/kubernetes/namespace/kanidm/default/repl-certs)
- VaultAuth + VaultStaticSecret sync certs to kanidm-repl-certs Secret
- busybox config-init init container injects peer certs from Secret into server.toml at startup
- Remove hardcoded partner_cert entries from per-pod server.toml templates
- Add automatic_refresh = true to all replication configs
- Add reloader.stakater.com/auto annotation to trigger rolling restart on ConfigMap/Secret changes
- Document domain UUID mismatch resolution and cert rotation in README

Reviewed-on: #176

apps/base/kanidm/vaultauth.yaml

@@ -0,0 +1,21 @@
+---
+apiVersion: secrets.hashicorp.com/v1beta1
+kind: VaultAuth
+metadata:
+  name: default
+  namespace: kanidm
+  labels:
+    app.kubernetes.io/name: kanidm
+    app.kubernetes.io/instance: kanidm
+spec:
+  method: kubernetes
+  mount: k8s/au/syd1
+  vaultConnectionRef: vso-system/default
+  allowedNamespaces:
+    - kanidm
+  kubernetes:
+    role: default
+    serviceAccount: kanidm
+    audiences:
+      - vault
+    tokenExpirationSeconds: 600