Bump cephrgw-operator CRDs to v0.3.0 (#286)

## Why

The `cephrgw-system` kustomization pinned the CRD source to **`raw/tag/v0.1.0/config/crd/install.yaml`**, so the in-cluster CRDs never gained the fields added since v0.1.0 — v0.2.0's fine-grained BucketAccess policy fields (`paths`/`actions`/`conditions`/`rawStatements`) and v0.3.0's adoption fields (`retainOnDelete`, `managePolicy`, `status.adopted`). The running operator is v0.3.0, so applying those specs fails with `strict decoding error: unknown field`. The image bumps (#273, #279) should have moved this tag too.

## Changes

- point the CRD `install.yaml` at `raw/tag/v0.3.0`

The tag must track the operator image tag on future bumps. Verified the v0.3.0 URL serves the new schema and `kustomize build` renders all 3 CRDs.

https://claude.ai/code/session_016CEncETbf8cvy1PhsHfFHM
Reviewed-on: #286
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

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/v0.1.0/config/crd/install.yaml
+  - https://git.unkin.net/unkin/cephrgw-operator/raw/tag/v0.3.0/config/crd/install.yaml
   - rbac.yaml
   - deployment.yaml
   - vaultauth.yaml