- Moved menu-related classes to a new structure under `src/menu/`.
- Introduced `WolfMenuPresentation` to handle menu art and mappings.
- Added `MenuManager` tests to ensure menu state reflects game status.
- Implemented `FlutterRendererSettingsPersistence` and `FlutterSaveGamePersistence` for managing settings and save files on desktop platforms.
- Created `Wolf3dFlutterInput` to handle keyboard and mouse input in a Flutter environment.
- Updated README to reflect new package structure and usage instructions.
Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>
