Bump bind-operator to v0.2.0 and deploy companion TSIG API (#249)

## Why

bind-operator v0.2.0 adds the `BindTSIGAPI` CRD and a companion API that `vault-plugin-secrets-bind-tsig` calls to create, rotate and delete TSIG keys (it does so by managing `BindTSIGKey` resources, which the operator reconciles into key material). This rolls the operator forward and deploys an API instance so Vault never talks to the Kubernetes API directly.

## Changes

- Bump the operator image (`bind-system/deployment.yaml`) and the pulled CRD bundle URL (`bind-system/kustomization.yaml`) to `v0.2.0`.
- Broaden the operator ClusterRole (`bind-system/rbac.yaml`) with `deployments`, `serviceaccounts` and `roles`/`rolebindings`, so the `BindTSIGAPI` reconciler can create the API Deployment and its namespaced Role/RoleBinding.
- Add a `BindTSIGAPI` (`bind-tsig-api`) in `bind-internal`; the operator reconciles it into a Deployment, Service, ConfigMap, master-token Secret and RBAC. Keys are created in `bind-internal`, alongside the authoritative cluster and its existing keys.
- Add the generated kubeconform schema for `BindTSIGAPI`.

## Notes

- The master access token Secret (`bind-tsig-api-token`) is generated by the operator when absent; the operator does not own it, so a `VaultStaticSecret` can later pre-seed/overwrite it to source the token from Vault.
- Validated: both overlays render (`kubectl kustomize`) and pass `kubeconform` (bind-internal 56/56 valid); pre-commit clean.

## Follow-up

- Point `vault-plugin-secrets-bind-tsig` config at `http://bind-tsig-api.bind-internal.svc:8443`.

Reviewed-on: #249
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

@@ -0,0 +1,27 @@
+---
+# Companion TSIG API. The operator reconciles this into a Deployment, Service,
+# ConfigMap, master-token Secret and namespaced RBAC. vault-plugin-secrets-bind-tsig
+# calls it to create/rotate/delete TSIG keys, which it does by managing
+# BindTSIGKey resources in this namespace (the operator reconciles the material).
+#
+# The master access token Secret (bind-tsig-api-token) is generated by the
+# operator if absent; a VaultStaticSecret may later pre-seed/overwrite it so the
+# token is sourced from Vault rather than generated in-cluster.
+apiVersion: bind.unkin.net/v1alpha1
+kind: BindTSIGAPI
+metadata:
+  name: bind-tsig-api
+  namespace: bind-internal
+spec:
+  image: git.unkin.net/unkin/bind-tsig-api:v0.2.0
+  replicas: 1
+  port: 8443
+  # targetNamespace defaults to this resource's namespace (bind-internal), where
+  # the authoritative cluster and its keys live.
+  resources:
+    requests:
+      cpu: 25m
+      memory: 64Mi
+    limits:
+      cpu: 250m
+      memory: 128Mi