- Add Theme class and THEME_REGISTRY to engine/themes.py
- Add set_active_theme() function to config.py
- Add msg_gradient() function to use theme-based message gradients
- Support --theme CLI flag to select theme (green, orange, purple)
- Initialize theme on module load with fallback to default
Two critical fixes:
1. ListDataSource Cache Bug
- Previously, ListDataSource.__init__ cached raw tuples directly
- get_items() would return cached raw tuples without converting to SourceItem
- This caused SourceItemsToBufferStage to receive tuples and stringify them
- Results: ugly tuple representations in terminal/pygame instead of formatted text
- Fix: Store raw items in _raw_items, let fetch() convert to SourceItem
- Cache now contains proper SourceItem objects
2. Camera Dependency Resolution
- CameraStage declared dependency on 'source.items' exactly
- DataSourceStage provides 'source.headlines' (or 'source.poetry', etc.)
- Capability matching didn't trigger prefix match for exact dependency
- Fix: Change CameraStage dependency to 'source' for prefix matching
3. Added app.py Camera Stage Support
- Pipeline now adds camera stage from preset.camera config
- Supports vertical, horizontal, omni, floating, bounce modes
- Tests now passing with proper data flow through all stages
Tests: All 502 tests passing, 16 skipped
