Students can run demos directly with Python, and developers can
run jupyter-book directly. The CLI wrappers don't add value.
Changes:
- Move demo.py and book.py to _archived/
- Remove from main.py command registry
- Remove from __init__.py imports
- Update test expectations (47 tests passing)
- Update archived README with removal rationale
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
