Refactor menu rendering and asset registry structure

- Updated SoftwareRenderer to incorporate MenuHeaderBand for handling spear variant menus and improved backdrop drawing.
- Refactored asset registry imports to organize menu-related assets under a dedicated menu structure.
- Enhanced game session snapshot tests to validate menu theme restoration for spear variant games.
- Added tests for classic menu presentation module to ensure palette consistency with canonical constants.
- Implemented tests for spear asset registry to verify correct menu VGA index resolutions.
- Created unit tests for MenuHeaderBand to validate functionality in rendering menu headers and sidebars.
- Adjusted HUD module imports to align with new menu structure.

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

apps/wolf_3d_gui/lib/main.dart

@@ -12,6 +12,10 @@ void main() async {
     debug: kDebugMode,
   ).init();
 
+  if (kDebugMode) {
+    wolf3d.enableMenuHeaderBandDebugLogging(prefix: '[wolf_3d_gui]');
+  }
+
   runApp(
     MaterialApp(
       home: Wolf3dGuiApp(engine: wolf3d),