Add detailed technical learnings and implementation notes

🔬 **Technical Documentation**

- Comprehensive code snippets with working solutions
- Analysis of approaches that worked vs didn't work
- Testing strategy innovations with specific examples
- Key learnings for future widget development
- Complete implementation reference with commit hashes

**Key Technical Solutions Documented**:
- Automatic widget display mechanism using IPython hooks
- Dynamic field visibility with layout.display property
- Real-time input validation with visual feedback
- Environment-independent testing strategies
- Configuration file detection and smart loading
- Advanced UI components (accordion, textarea parsing)

**Commit References**: 23993e6, 40cef68

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

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

Author: jeremymanning