Track a stable REST fixture image for scan-planning integration tests

### Context

The Java scan-planning integration suite introduced in #1505 currently uses this digest-pinned image:

apache/iceberg-rest-fixture:latest@sha256:db8de90b5b7693d4ac334c336f91d9bbe320d7b19f4f514d26de84cdfbcbfe8d

Apache Iceberg 1.11.0 has been released, but Docker Hub does not currently publish an `apache/iceberg-rest-fixture:1.11.0` tag. The newest versioned fixture tag is still 1.10.1, which predates scan-planning support.

### Done when

- A stable, versioned REST fixture image containing scan-planning support is available.
- `internal/recipe/docker-compose.yml` is updated from the `latest@sha256` pin to that stable tag.
- `make integration-rest-scan-planning` passes with the stable image.

Follow-up to #1505 and #1878.

Start with internal/recipe/docker-compose.yml and inspect the image reference used by the scan-planning integration suite. Check which stable REST fixture image tag contains scan-planning support, then run make integration-rest-scan-planning. Done means the compose file uses that stable versioned image and the integration command passes.

Written by the indexing model from the issue text.