- Add test-heavy.json book with 156 advanced academic vocabulary terms
- Add test-heavy-stress.json chapter for system stress testing
- Update UnifiedDRS with ContentDependencyAnalyzer integration
- Update VocabularyModule for unified persistence system
- Update progress saves with test data
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
