Release v0.2.0 - DuckDB Extension Support

### Major Features Added:
- Comprehensive DuckDB extension management system
- ExtensionManager for loading, listing, and managing extensions
- ExtensionHelper with predefined extension groups
- Support for preloading extensions during initialization
- Extension-aware dialector variants

### API Additions:
- OpenWithExtensions() and NewWithExtensions() functions
- GetExtensionManager() and MustGetExtensionManager() helpers
- ExtensionConfig for auto-installation and preloading
- Built-in support for common extensions (JSON, Parquet, CSV, Spatial)

### Bug Fixes:
- Fixed db.DB() method access to underlying *sql.DB
- Repository cleanup and package conflict resolution
- Improved .gitignore to prevent binary commits

### Testing:
- Comprehensive test suite for all extension functionality
- Functional tests with real DuckDB extension operations
- 100% test pass rate for extension features

This is a significant feature release that adds powerful DuckDB extension
support while maintaining full backward compatibility.

Author: greysquirr3l

RELEASE.md

@@ -129,4 +129,4 @@ See CONTRIBUTING.md for development setup and guidelines.
 ## 📄 License
 
 MIT License
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