Root nodes join through ModRoot.AddDeferred, so a reload that unloads the mod first never hands Godot a freed node

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/StudioLaunchInitializer.cs

@@ -29,13 +29,12 @@ namespace Cthangover.Mods.ScenarioStudio
             var layer = new StudioLayer(args);
             layer.Mount();
 
-            var root = (Godot.Engine.GetMainLoop() as SceneTree)?.Root;
-            root?.CallDeferred("add_child", new StudioLive(layer));
+            ModRoot.AddDeferred(new StudioLive(layer));
 
             if (!args.Contains(Flag))
                 return;
             GameLogger.Log("UI", "Scenario studio: --studio given, the dock opens with the first scene");
-            root?.CallDeferred("add_child", new StudioAutoOpenNode());
+            ModRoot.AddDeferred(new StudioAutoOpenNode());
         }
     }
 }

test_suites/live/src/StudioLiveTestInitializer.cs

@@ -35,7 +35,7 @@ namespace Cthangover.Mods.ScenarioStudio.Tests.Live
 
             driverQueued = true;
             GameLogger.Log("TEST", $"StudioLiveTestInitializer: activating studio live test, shots='{shots ?? ""}'");
-            (Godot.Engine.GetMainLoop() as SceneTree)?.Root?.CallDeferred("add_child", new StudioLiveDriverNode(shots));
+            ModRoot.AddDeferred(new StudioLiveDriverNode(shots));
         }
     }
 }