- Add Document class (include/document.h, source/document.cpp)
- JSON serialization/deserialization of DesignerScene
- State management: filename, modified flag, timestamps, metadata
- File operations: New, Open, Save with .bay extension
- Integrate Document into CMainWindow
- initializeDocument() to create and associate with DesignerScene
- File menu actions connected to Document methods
- Window title updates on modified/filename changes
- Close event checks for unsaved changes
- Update CLAUDE.md with Document architecture documentation
Jesse Qu