package.json has no engines field pinning a Node.js version, despite CI hardcoding Node 24

[chonilius]

.github/workflows/ci.yml pins node-version: 24 via actions/setup-node@v4, and the Dockerfile uses node:24-alpine as its base image — both hard commitments to a specific, quite new major Node version. package.json has no "engines": { "node": ">=24" } field declaring this as a project requirement. A contributor developing locally on an older (even LTS) Node version gets no npm install/npm run warning that they're on an unsupported runtime, and could hit subtly different behavior than CI without any signal pointing at the version mismatch as the cause.