Bump bind-operator to v0.2.1 (secondary replication fix) (#250)

## Why

v0.2.1 fixes authoritative **secondary replication**, which never actually worked — the master REFUSED the catalog AXFR. Root causes (bind-operator #9): secondaries presented no TSIG key, member zones had no `allow-transfer`, and secondaries pointed at the primary's ephemeral pod IP.

## Changes

- Bump the operator image (`bind-system/deployment.yaml`) and the pulled CRD bundle URL (`bind-system/kustomization.yaml`) to `v0.2.1`.
- Bump the `bind-tsig-api` image (`bind-internal/tsig-api/tsig-api.yaml`) to `v0.2.1`.

CRDs are unchanged from v0.2.0, so the generated kubeconform schemas need no update.

## Validation

- `bind-system` renders with the v0.2.1 CRD bundle; `bind-internal` passes `kubeconform` (56/56); pre-commit clean.

## Deploy note

Existing member zones pick up `allow-transfer` via `modzone`, and secondaries re-point at the stable primary Service ClusterIP with the transfer key, restoring replication without manual BIND surgery. A from-scratch namespace recreate also comes up clean (OrderedReady startup means secondaries snapshot a ClusterIP-correct config). Caveat for a full recreate: the operator regenerates the `client-update` TSIG key, so its new material must be re-synced into puppet eyaml before clients can nsupdate.

Reviewed-on: #250
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

apps/base/bind-internal/tsig-api/tsig-api.yaml

@@ -13,7 +13,7 @@ metadata:
   name: bind-tsig-api
   namespace: bind-internal
 spec:
-  image: git.unkin.net/unkin/bind-tsig-api:v0.2.0
+  image: git.unkin.net/unkin/bind-tsig-api:v0.2.1
   replicas: 1
   port: 8443
   # targetNamespace defaults to this resource's namespace (bind-internal), where