- Update package.json to require Node.js >=25
- Add .nvmrc file with Node.js version 25
- Update README.md with Node.js 25 requirements
- Add fnm installation and usage instructions
- Update both English and Polish documentation sections
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>