Update Node.js support and CI to 22.22.3

[Copilot]

This updates the repository’s Node.js baseline from v20 to the latest compatible v22 minor, aligning local/runtime constraints with CI. The change is limited to version declarations because the existing dependency set and test/build flow remain compatible on Node 22.

• Runtime support

  • Updates package.json engines.node from ^20 to ^22.22.3

• CI alignment

  • Updates the GitHub Actions test workflow to run on 22.22.3
  • Keeps dependency caching and the existing test job structure unchanged

• Version declaration example

  "engines": {
    "node": "^22.22.3"
  }