Release v2.1.0 - Async Tools & Input Validation and added tools support in library

New Features:

• Async tool support for non-blocking I/O
• Comprehensive input validation (pattern, range, length, choice, custom)
• 5 built-in async tools (fetch_url, post_json, async file ops)
• Enhanced tool system with validation

Breaking Changes: None
Backwards Compatible: Yes"

Full Changelog: v2.0.0...v2.1.0