actionlint over stable-release.yml, publish-release.yml, canary.yml,
and itself; shellcheck (severity warning) over scripts/release shell
scripts; and the release-scope-dropdown-sync job running
verify-release-scope-dropdowns.sh. Scope intentionally narrow to the
release pipelines to avoid drowning unrelated changes in lint noise.
Ported from ag-ui-protocol/ag-ui.
Maxim