The `js-deps` stage installed ESLint and prettier with yarn 1, which is no longer developed and made node print a `url.parse()` deprecation warning on every install. `package.json` now pins yarn 4 by version and hash in its `packageManager` field; the stage enables it through the node image's own corepack and installs with `yarn install --immutable`. `yarn.lock` is regenerated in yarn 4's format with every package at its previously locked version, and `.yarnrc.yml` keeps the install in `node_modules/`, where the lint and Markdown stages run the tools from. The install prints no warning and stays cached until the manifests change.
Model: opus-5-5
