Rework dimmable audio stream

Zennysoft.Game.Ma/src/map/dungeon/code/Overworld.cs

@@ -1,6 +1,8 @@
 using Chickensoft.AutoInject;
 using Chickensoft.Introspection;
 using Godot;
+using System.Linq;
+using Zennysoft.Game.Abstractions;
 using Zennysoft.Ma.Adapter;
 
 namespace Zennysoft.Game.Ma;
@@ -19,6 +21,8 @@ public partial class Overworld : SpecialFloor, IDungeonFloor
 
   [Node] private Area3D RestoreArea { get; set; } = default!;
 
+  [Node] private Node DimmableAudio { get; set; } = default!;
+
   private Timer RestoreTimer { get; set; }
 
   public override void InitializeDungeon()
@@ -32,6 +36,17 @@ public partial class Overworld : SpecialFloor, IDungeonFloor
     RestoreTimer.Timeout += RestoreTimer_Timeout;
     AddChild(RestoreTimer);
     FloorIsLoaded = true;
+
+    var dimmableAudio = DimmableAudio.GetChildren().OfType<IDimmableAudioStreamPlayer>();
+    foreach (var dimmable in dimmableAudio)
+      dimmable.FadeIn();
+  }
+
+  public override void FadeOutAudio()
+  {
+    var dimmableAudio = DimmableAudio.GetChildren().OfType<IDimmableAudioStreamPlayer>();
+    foreach (var dimmable in dimmableAudio)
+      dimmable.FadeOut();
   }
 
   private void RestoreTimer_Timeout()