FLPATH-4770 - bump control-plane and add check-website-fixtures workflow

[testetson22]

FLPATH-4770: The CLI's go.mod pinned control-plane to a commit predating the multi-resource schema change (FLPATH-4384). This caused parseInputFileAs to silently drop the spec.resources field during YAML → JSON serialization, making it impossible to create catalog items via dcm catalog item create.

check-website-fixtures action is expected to fail until the dcm-project.github.io PR is merged.

Changes

• Bump github.com/dcm-project/control-plane to latest main so the CLI's generated types include the Resources field required by the multi-resource catalog item schema
• Add static contract tests (TC-U154, TC-U155) that validate the CLI correctly serializes documented tutorial YAMLs to the API
• Add testdata/website/ fixtures mirroring the Getting Started tutorial examples
• Add hack/check-website-fixtures.sh script + CI workflow to detect drift between local fixtures and the upstream website repo

Depends on

• FLPATH-4770 - fix getting started examples for multi-resource catalog items dcm-project.github.io#21 - Website: updates tutorial YAMLs to multi-resource schema (dcm-project/dcm-project.github.io branch FLPATH-4770-fix-user-journey)

Test plan

• go test ./... passes (151 specs including 2 new contract tests)
• Contract tests validate the exact YAML→JSON serialization path that was broken
• hack/check-website-fixtures.sh correctly detects drift (verified locally)
• ShellCheck passes on the script
• hugo --minify confirms companion website changes render correctly

Related

• FLPATH-4794 — Add CLI-to-API contract tests to prevent silent schema drift