Release v1.2.0

Release v1.1.0: major refactor, CLI, tests, Docker, and UI improvements

- Refactored ltc_generator.py and app.py with significant enhancements
- Added CLI interface (cli.py) and pyproject.toml for proper packaging
- Added comprehensive test suite (pytest) with benchmarks and real decode tests
- Added Dockerfile for containerized deployment
- Updated web UI (index.html, script.js, styles.css) with improved UX
- Updated requirements.txt and added requirements-dev.txt
- Fixed macOS release upload step in build.yml
- Added IMPROVEMENTS.md and ISSUES.md documentation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Update build.yml