Release v0.5.2: Parser Performance Optimizations

Major Performance Improvements:
- StaxXmlParserSync: +20.67% performance improvement
  - Eliminated Generator overhead
  - Implemented State Machine pattern
  - 10MB file: 115.98ms → 92.00ms

- StaxXmlParser: ~15% performance improvement
  - Replaced Array.shift() O(n) with Circular Buffer O(1)
  - 1GB files show 15% improvement
  - Queue operations: 50ns → 10ns

Quality Assurance:
- All 796 tests passing
- Comprehensive benchmark suite
- Backward compatible API

Documentation:
- PARSER_OPTIMIZATION_FINAL_REPORT.md
- Lessons learned from 5 failed optimizations
- Best practices for V8 optimization

See commit 242f464 for detailed changes.

Release v0.5.1 - Update package README and publish workflow

Release v0.5.0 - Add declarative XML converter with XPath support

v0.4.0 Release

Performance Improvements:
- Optimization for V8 hidden class
- StaxXmlParserSync: unnecessary substring operations removed
- Caching entity regex for better performance
- Inline functions to reduce function call overhead

API Changes:
- **Breaking**: StaxXmlWriter is now async-based, synchronous version moved to StaxXmlWriterSync

Documentation & Testing:
- Added documentation using Astro Starlight
- Added several performance benchmarks

Major performance improvements and breaking changes for better async handling.