feat: Enhance CLI and GUI to support configurable game data directory persistence

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

packages/wolf_3d_flutter/lib/screens/no_game_data_screen.dart

@@ -1,15 +1,42 @@
 library;
 
 import 'package:flutter/material.dart';
+import 'package:wolf_3d_dart/wolf_3d_data_types.dart';
+import 'package:wolf_3d_dart/wolf_3d_menu.dart';
 
 /// Fallback screen shown when no Wolf3D game data files are discovered.
 class NoGameDataScreen extends StatelessWidget {
-  const NoGameDataScreen({super.key});
+  const NoGameDataScreen({
+    super.key,
+    this.configuredDataDirectory,
+  });
+
+  /// Previously configured external game-data directory, if any.
+  final String? configuredDataDirectory;
+
+  static Color _colorFromVgaIndex(int index) {
+    final int packed = ColorPalette.vga32Bit[index]; // 0xAABBGGRR
+    final int r = packed & 0xFF;
+    final int g = (packed >> 8) & 0xFF;
+    final int b = (packed >> 16) & 0xFF;
+    return Color((0xFF << 24) | (r << 16) | (g << 8) | b);
+  }
+
+  static final Color _backgroundColor = _colorFromVgaIndex(111);
+  static final Color _panelColor = _colorFromVgaIndex(103);
+  static final Color _borderColor = _colorFromVgaIndex(87);
+  static final Color _titleColor = _colorFromVgaIndex(
+    WolfMenuPalette.headerTextIndex,
+  );
+  static final Color _bodyColor = _colorFromVgaIndex(
+    WolfMenuPalette.unselectedTextIndex,
+  );
+  static final Color _emphasisColor = _colorFromVgaIndex(10);
 
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      backgroundColor: const Color(0xFF140000),
+      backgroundColor: _backgroundColor,
       body: Center(
         child: Padding(
           padding: const EdgeInsets.all(24),
@@ -17,10 +44,10 @@ class NoGameDataScreen extends StatelessWidget {
             constraints: const BoxConstraints(maxWidth: 640),
             child: DecoratedBox(
               decoration: BoxDecoration(
-                color: const Color(0xFF590002),
-                border: Border.all(color: const Color(0xFFB00000), width: 2),
+                color: _panelColor,
+                border: Border.all(color: _borderColor, width: 2),
               ),
-              child: const Padding(
+              child: Padding(
                 padding: EdgeInsets.all(20),
                 child: Column(
                   mainAxisSize: MainAxisSize.min,
@@ -29,25 +56,44 @@ class NoGameDataScreen extends StatelessWidget {
                     Text(
                       'WOLF3D DATA NOT FOUND',
                       style: TextStyle(
-                        color: Color(0xFFFFF700),
+                        color: _titleColor,
                         fontSize: 24,
                         fontWeight: FontWeight.bold,
                       ),
                     ),
-                    SizedBox(height: 16),
+                    const SizedBox(height: 16),
                     Text(
                       'No game files were discovered.\n\n'
-                      'Add Wolfenstein 3D data files to one of these locations:\n'
-                      '- packages/wolf_3d_assets/assets/retail\n'
-                      '- packages/wolf_3d_assets/assets/shareware\n'
-                      '- or a discoverable local game-data folder.\n\n'
-                      'Restart the app after adding the files.',
+                      'Select a game-data directory in setup.',
                       style: TextStyle(
-                        color: Colors.white,
+                        color: _bodyColor,
                         fontSize: 15,
                         height: 1.4,
                       ),
                     ),
+                    const SizedBox(height: 12),
+                    Text(
+                      'Once all required files are present, the game starts automatically.',
+                      style: TextStyle(
+                        color: _emphasisColor,
+                        fontSize: 14,
+                        height: 1.35,
+                        fontWeight: FontWeight.w600,
+                      ),
+                    ),
+                    if (configuredDataDirectory != null &&
+                        configuredDataDirectory!.trim().isNotEmpty)
+                      Padding(
+                        padding: const EdgeInsets.only(top: 12),
+                        child: Text(
+                          'Configured data directory: ${configuredDataDirectory!.trim()}',
+                          style: TextStyle(
+                            color: _bodyColor,
+                            fontSize: 13,
+                            height: 1.3,
+                          ),
+                        ),
+                      ),
                   ],
                 ),
               ),