Roll cephrgw-operator to v0.3.1 (CRD staleness warning) (#290)

## Why

cephrgw-operator **v0.3.1** logs a startup WARNING when its installed CRDs are missing or older than the operator (operator repo #6, merged) — added precisely because the CRD tag drifted behind the image before. The new startup check reads the `CustomResourceDefinition` objects, so it needs a small RBAC grant.

## Changes

- bump the operator image `git.unkin.net/unkin/cephrgw-operator` → `v0.3.1`
- bump the CRD `install.yaml` tag → `v0.3.1` (keep CRDs in step with the image — the invariant the v0.3.1 warning enforces)
- add `apiextensions.k8s.io/customresourcedefinitions: [get, list]` to the operator ClusterRole so the startup check is not RBAC-denied

Validated with `kustomize build` on the au-syd1 overlay; the v0.3.1 CRD URL resolves. Supersedes nothing outstanding (the earlier CRD-tag PR #286 to v0.3.0 already merged).

https://claude.ai/code/session_016CEncETbf8cvy1PhsHfFHM
Reviewed-on: #290
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

apps/base/cephrgw-system/deployment.yaml

@@ -24,7 +24,7 @@ spec:
         runAsNonRoot: true
       containers:
         - name: operator
-          image: git.unkin.net/unkin/cephrgw-operator:v0.3.0
+          image: git.unkin.net/unkin/cephrgw-operator:v0.3.1
           args:
             - --metrics-bind-address=:8080
             - --health-probe-bind-address=:8081

apps/base/cephrgw-system/kustomization.yaml

@@ -6,7 +6,7 @@ resources:
   - namespace.yaml
   # CRDs are pulled from the cephrgw-operator repo at the matching tag rather
   # than vendored here, so they never drift from the operator.
-  - https://git.unkin.net/unkin/cephrgw-operator/raw/tag/v0.3.0/config/crd/install.yaml
+  - https://git.unkin.net/unkin/cephrgw-operator/raw/tag/v0.3.1/config/crd/install.yaml
   - rbac.yaml
   - deployment.yaml
   - vaultauth.yaml

apps/base/cephrgw-system/rbac.yaml

@@ -23,6 +23,10 @@ rules:
   - apiGroups: ["coordination.k8s.io"]
     resources: ["leases"]
     verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
+  # v0.3.1 startup check reads its own CRDs to warn if they are stale/missing.
+  - apiGroups: ["apiextensions.k8s.io"]
+    resources: ["customresourcedefinitions"]
+    verbs: ["get", "list"]
 ---
 apiVersion: rbac.authorization.k8s.io/v1
 kind: ClusterRoleBinding