Document Node.js version compatibility strategy

[bntvllnt]

Problem

Package requires Node >= 22 (engines field). Enterprise users on Node 20 LTS may be blocked.

Action

• Document why Node 22+ is required (or if it's necessary)
• If Node 20 support is feasible, add it
• If not, document EOL/migration path in README
• Consider adding Node 20 to CI matrix for testing

Priority

Low — depends on user base. Node 20 LTS support ends Oct 2026.