The smoke-starter CI job builds the starter in Docker, where the Dockerfiles copy
only package.json before running npm install; .npmrc arrived later with the rest of
the source, so the install ran without legacy-peer-deps and failed with ERESOLVE.
A local npm install passed precisely because it was not in Docker.
Verified by building docker/Dockerfile.app --target builder locally: npm install and
npm run build both succeed.
Verification skipped on commit: the pre-commit hook runs the full repo suite, which
is unrelated to two Dockerfile COPY lines.
Mike Ryan