- Add String.fromChar function to convert Char to String
- Create four stress test projects demonstrating Lux features:
- json-parser: recursive descent parsing with Char handling
- markdown-converter: string manipulation and ADTs
- todo-app: list operations and pattern matching
- mini-interpreter: AST evaluation and environments
- Add comprehensive testing documentation (docs/testing.md)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>