Add enhanced OpenContext parquet analysis tutorial

- Comprehensive property graph model documentation
- Interactive DuckDB-WASM based analysis in browser
- Corrected sample location queries with proper graph traversal
- Educational content about archaeological data relationships
- Performance optimization strategies for large datasets

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: rdhyee