refactor: SaveSystem now uses a DTO for player state serialization and PlayerDeathComponent delegates state changes to event handlers.

scripts/components/PlayerDeathComponent.cs

@@ -32,7 +32,7 @@ public partial class PlayerDeathComponent : Node2D
             effect.Scale = EffectScale;
         }
 
-        _gameManager.RemoveLives(1);
-        _gameManager.ResetCurrentSessionState();
+        // Lives are now decremented by LivesStateHandler via PlayerDied event
+        // Session state is reset by LivesStateHandler as well
     }
 }