David Gwilliam
6fc3cbc0d2
refactor(remove): Delete RenderStage and ItemsStage classes (Phase 4.3)
- Delete RenderStage class (124 lines) - used legacy rendering
- Delete ItemsStage class (32 lines) - deprecated bootstrap mechanism
- Delete create_items_stage() function (3 lines)
- Add ListDataSource class to wrap pre-fetched items (38 lines)
- Update app.py to use ListDataSource + DataSourceStage instead of ItemsStage
- Remove deprecated test methods for RenderStage and ItemsStage
- Tests pass (508 core tests, legacy failures pre-existing)