Refactor and enhance documentation across the Wolf3D project

- Updated library imports to use the correct package paths for consistency.
- Added detailed documentation comments to various classes and methods, improving code readability and maintainability.
- Refined the GameSelectScreen, SpriteGallery, and VgaGallery classes with clearer descriptions of their functionality.
- Enhanced the CliInput class to better explain the input handling process and its interaction with the engine.
- Improved the SixelRasterizer and Opl2Emulator classes with comprehensive comments on their operations and state management.
- Removed the deprecated wolf_3d.dart file and consolidated its functionality into wolf_3d_flutter.dart for a cleaner architecture.
- Updated the Wolf3dFlutterInput class to clarify its role in merging keyboard and pointer events.
- Enhanced the rendering classes to provide better context on their purpose and usage within the Flutter framework.

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

apps/wolf_3d_gui/lib/main.dart

@@ -1,7 +1,14 @@
+/// Flutter entry point for the GUI host application.
+///
+/// The GUI bootstraps bundled and discoverable game data through [Wolf3d]
+/// before presenting the game-selection flow.
+library;
+
 import 'package:flutter/material.dart';
-import 'package:wolf_3d_flutter/wolf_3d.dart';
+import 'package:wolf_3d_flutter/wolf_3d_flutter.dart';
 import 'package:wolf_3d_gui/screens/game_select_screen.dart';
 
+/// Creates the application shell after loading available Wolf3D data sets.
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();