feat(render): add meshlet rendering and ECS query ref API

Introduces meshlet-based rendering pipeline with new HLSL structures and push constant layouts. Refactors meshlet upload/cooking, updates RenderGraphContext for global/view/instance data, and enhances ECS QueryBuilder with ref returns and [UnscopedRef] for fluent chaining. Improves resource management and disposal patterns, updates D3D12 interop for compatibility, and refines test/app infrastructure. Includes dependency updates, bug fixes, and code cleanups.

src/Runtime/Ghost.Entities/System.cs

@@ -340,7 +340,7 @@ public abstract class SystemGroup : ISystem
 
 public sealed class DefaultSystemGroup : SystemGroup;
 
-public sealed class SystemManager
+public sealed class SystemManager : IDisposable
 {
     private readonly World _world;
 
@@ -415,4 +415,9 @@ public sealed class SystemManager
             system.Cleanup(in systemAPI);
         }
     }
+
+    public void Dispose()
+    {
+        CleanupAll(default);
+    }
 }