Don't zero-init singleton components

src/gaemstone.Client/Systems/ImGuiManager.cs

@@ -29,10 +29,7 @@ public partial class ImGuiManager
 	[DependsOn<Pipeline.OnStore>]
 	public struct ImGuiRenderPhase {  }
 
-	// Start out disabled, because we first need to set it with a valid instance.
+	[Singleton]
-	// TODO: Add a hint when a Singleton class is used without adding Disabled.
-	// TODO: Add a [Disabled] attribute as shortcut?
-	[Singleton, Add<Core.Disabled>]
 	public class ImGuiData
 	{
 		public ImGuiController Controller { get; }
@@ -91,7 +88,7 @@ public partial class ImGuiManager
 	[DependsOn<Pipeline.OnLoad>]
 	public static unsafe void Initialize<T>(World<T> world, GameWindow window, Canvas canvas,
 			[Source<Input>] InputContext inputContext, Not<ImGuiData> _)
-		=> world.Entity<ImGuiData>().Enable().Set(new ImGuiData(
+		=> world.Entity<ImGuiData>().Set(new ImGuiData(
 			new(canvas.GL, window.Handle, inputContext.Value, () => {
 				var io    = ImGui.GetIO();
 				var style = ImGui.GetStyle();

src/gaemstone.SourceGen/ModuleGenerator.cs

@@ -175,7 +175,10 @@ public class ModuleGenerator
 				else               sb.Append($".CreateLookup<{e.FullName}>()");
 				                   sb.AppendLine();
 
-				if (e.IsSingleton) sb.AppendLine($"\t\t\t.Add<{e.FullName}>()");
+				// I don't think it makes sense to have singletons pre-initialized to zero.
+				// Especially for singletons that are reference types, which would default to null.
+				// if (e.IsSingleton) sb.AppendLine($"\t\t\t.Add<{e.FullName}>()");
+				// TODO: Look into if it would be possible to detect if we have field initializers.
 			}
 
 			sb.Insert(sb.Length - 1, ";");