refactor: move zIndex to parent

lib/game/components/google_gallery/google_gallery.dart

@@ -4,12 +4,13 @@ import 'package:flutter/material.dart';
 import 'package:pinball/game/behaviors/behaviors.dart';
 import 'package:pinball/game/components/google_gallery/behaviors/behaviors.dart';
 import 'package:pinball_components/pinball_components.dart';
+import 'package:pinball_flame/pinball_flame.dart';
 
 /// {@template google_gallery}
 /// Middle section of the board containing the [GoogleWord] and the
 /// [GoogleRollover]s.
 /// {@endtemplate}
-class GoogleGallery extends Component {
+class GoogleGallery extends Component with ZIndex {
   /// {@macro google_gallery}
   GoogleGallery()
       : super(
@@ -34,7 +35,9 @@ class GoogleGallery extends Component {
               ],
             ),
           ],
-        );
+        ) {
+    zIndex = ZIndexes.decal;
+  }
 
   /// Creates a [GoogleGallery] without any children.
   ///

packages/pinball_components/lib/src/components/google_rollover/google_rollover.dart

@@ -2,12 +2,11 @@ import 'package:flame/components.dart';
 import 'package:flame_forge2d/flame_forge2d.dart';
 import 'package:pinball_components/pinball_components.dart';
 import 'package:pinball_components/src/components/google_rollover/behaviors/behaviors.dart';
-import 'package:pinball_flame/pinball_flame.dart';
 
 /// {@template google_rollover}
 /// Rollover that lights up [GoogleLetter]s.
 /// {@endtemplate}
-class GoogleRollover extends BodyComponent with ZIndex {
+class GoogleRollover extends BodyComponent {
   /// {@macro google_rollover}
   GoogleRollover({
     required BoardSide side,
@@ -21,9 +20,7 @@ class GoogleRollover extends BodyComponent with ZIndex {
             _PinSpriteAnimationComponent(side: side),
             ...?children,
           ],
-        ) {
-    zIndex = ZIndexes.decal;
-  }
+        );
 
   final BoardSide _side;
 

packages/pinball_components/lib/src/components/google_word/google_word.dart

@@ -1,13 +1,12 @@
 import 'package:flame/components.dart';
 import 'package:pinball_components/pinball_components.dart';
-import 'package:pinball_flame/pinball_flame.dart';
 
 export 'cubit/google_word_cubit.dart';
 
 /// {@template google_word}
 /// Loads all [GoogleLetter]s to compose a [GoogleWord].
 /// {@endtemplate}
-class GoogleWord extends PositionComponent with ZIndex {
+class GoogleWord extends PositionComponent {
   /// {@macro google_word}
   GoogleWord({
     required Vector2 position,
@@ -21,7 +20,5 @@ class GoogleWord extends PositionComponent with ZIndex {
             GoogleLetter(4)..position = Vector2(8.33, -0.75),
             GoogleLetter(5)..position = Vector2(13.1, 1.72),
           ],
-        ) {
-    zIndex = ZIndexes.decal;
-  }
+        );
 }