feat: enhance framework integration and simplify codebase
- Simplify universal modules to be more framework-friendly
- Add comprehensive framework integration documentation (Next.js, Vue, React)
- Implement missing relateMany() batch relationship creation method
- Clean up obsolete test files and improve test coverage
- Reduce browser polyfill complexity while maintaining compatibility
- Remove unused browserFramework entry points for cleaner API surface
📄 3,120 lines added, 3,679 lines removed for net simplification