feat: Add bonus flash effect for player pickups and update rendering logic

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

packages/wolf_3d_dart/test/rendering/hud_lives_rendering_test.dart

@@ -46,17 +46,38 @@ void main() {
     expect(expectedNoKeyIndex, isNotNull);
 
     final goldKeyCall = renderer.drawCalls.firstWhere(
-      (call) => call.startY == 164 && call.startX == 30,
+      (call) => call.startY == 164 && call.startX == 240,
       orElse: () => throw StateError('Gold key slot was not rendered.'),
     );
     final silverKeyCall = renderer.drawCalls.firstWhere(
-      (call) => call.startY == 180 && call.startX == 30,
+      (call) => call.startY == 180 && call.startX == 240,
       orElse: () => throw StateError('Silver key slot was not rendered.'),
     );
 
     expect(goldKeyCall.imageIndex, expectedGoldKeyIndex);
     expect(silverKeyCall.imageIndex, expectedNoKeyIndex);
   });
+
+  test('standard VGA HUD face follows current health band', () {
+    final engine = _buildEngine();
+    engine.init();
+    engine.player.health = 20;
+
+    final renderer = _HudProbeRenderer(vgaImages: engine.data.vgaImages);
+    renderer.drawHudForTest(engine);
+
+    final expectedFaceIndex = engine.data.registry.hud
+        .faceForHealth(engine.player.health)
+        ?.vgaIndex;
+    expect(expectedFaceIndex, isNotNull);
+
+    final faceCall = renderer.drawCalls.firstWhere(
+      (call) => call.startY == 164 && call.startX == 136,
+      orElse: () => throw StateError('Face slot was not rendered.'),
+    );
+
+    expect(faceCall.imageIndex, expectedFaceIndex);
+  });
 }
 
 class _HudProbeRenderer extends RendererBackend<int> {