scripts/check-node-modules.mjs and gen-changelog.mjs run in check and release but sat outside
every lane: the eslint and prettier lanes run from frontend/, and an ESLint config cannot reach
past its own directory. A contract test now holds them to the js-configs bar (recommended rules
under Node, the frontend's Prettier style); an unused variable and the old formatting are each
red. 0 lint hits; both files reformatted. Registered in docs/gates.md.