fix: resolve ES module compatibility issues with dual-module setup

🔧 Module System Fixes:
- Update build process to output .cjs files for CommonJS compatibility
- Add build:rename script to convert .js to .cjs extensions
- Update package.json main entry to point to build/server.cjs
- Update bin entry to use build/server.cjs
- Restore 'type': 'module' for Smithery.ai compatibility

📦 Dual Module Support:
- CommonJS: build/server.cjs (for npm/CLI usage)
- ES Modules: src/index.ts (for Smithery.ai deployment)
- Jest configs: .cjs extensions (for test compatibility)

✅ Verification Results:
- npm run test:ci: ✅ 31 tests pass
- npm run build: ✅ Creates .cjs files correctly
- npm run build:smithery: ✅ ES modules for Smithery
- require('./build/server.cjs'): ✅ CommonJS import works
- Server startup: ✅ CLI functionality preserved

This resolves the 'require() of ES Module not supported' error
while maintaining compatibility with both traditional npm usage
and modern Smithery.ai deployment requirements.

Author: makafeli