- Changed QPointer<MapGraphicsView> to raw pointer MapGraphicsView*
- QPointer in Qt6 requires complete type at point of use, forward declaration insufficient
- MapGraphicsView.h requires GRAPHICSVIEW_SUPPORTED macro which is now defined
- Added GRAPHICSVIEW_SUPPORTED definition guard in overview_map_handler_impl.h
- Updated widget() method to return raw pointer instead of QPointer::data()
- Updated createBasicOverviewMap() to use direct new instead of QPointer constructor
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>