feat: Implement player locomotion constants and update movement logic in engine

feat: Add key icons to HUD modules and implement key rendering in HUD
test: Add player movement and rotation parity tests to ensure consistency with classic Wolf3D
test: Enhance HUD rendering tests for gold and silver key icons

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

packages/wolf_3d_dart/test/rendering/hud_lives_rendering_test.dart

@@ -27,6 +27,36 @@ void main() {
 
     expect(livesDigitCall.imageIndex, expectedDigitIndex);
   });
+
+  test('standard VGA HUD renders gold key icon when collected', () {
+    final engine = _buildEngine();
+    engine.init();
+    engine.player.hasGoldKey = true;
+
+    final renderer = _HudProbeRenderer(vgaImages: engine.data.vgaImages);
+    renderer.drawHudForTest(engine);
+
+    final expectedGoldKeyIndex = engine.data.registry.hud
+        .resolve(HudKey.goldKeyIcon)
+        ?.vgaIndex;
+    final expectedNoKeyIndex = engine.data.registry.hud
+        .resolve(HudKey.noKeyIcon)
+        ?.vgaIndex;
+    expect(expectedGoldKeyIndex, isNotNull);
+    expect(expectedNoKeyIndex, isNotNull);
+
+    final goldKeyCall = renderer.drawCalls.firstWhere(
+      (call) => call.startY == 164 && call.startX == 30,
+      orElse: () => throw StateError('Gold key slot was not rendered.'),
+    );
+    final silverKeyCall = renderer.drawCalls.firstWhere(
+      (call) => call.startY == 180 && call.startX == 30,
+      orElse: () => throw StateError('Silver key slot was not rendered.'),
+    );
+
+    expect(goldKeyCall.imageIndex, expectedGoldKeyIndex);
+    expect(silverKeyCall.imageIndex, expectedNoKeyIndex);
+  });
 }
 
 class _HudProbeRenderer extends RendererBackend<int> {

packages/wolf_3d_dart/test/rendering/map_overlay_renderer_test.dart

@@ -45,7 +45,8 @@ void main() {
       expect(changedPixels, greaterThan(mapPixels.length ~/ 5));
       expect(mapPixels.contains(ColorPalette.vga32Bit[6]), isTrue);
       expect(mapPixels.contains(ColorPalette.vga32Bit[12]), isTrue);
-      expect(mapPixels.contains(ColorPalette.vga32Bit[10]), isTrue);
+      expect(mapPixels.contains(ColorPalette.vga32Bit[15]), isTrue);
+      expect(mapPixels.contains(ColorPalette.vga32Bit[2]), isTrue);
       expect(mapPixels[hudProbeIndex], equals(normalPixels[hudProbeIndex]));
     });
   });
@@ -78,6 +79,7 @@ WolfEngine _buildEngine() {
   wallGrid[5][5] = 1;
   objectGrid[2][2] = MapObject.playerEast;
   objectGrid[5][5] = MapObject.pushwallTrigger;
+  objectGrid[10][10] = MapObject.normalExitTrigger;
 
   return WolfEngine(
     data: WolfensteinData(