feat(rhi)!: refactor resource handles to GPUTexture/GPUBuffer

Refactored all graphics resource handles to use Handle<GPUTexture> and Handle<GPUBuffer> instead of Handle<Texture> and Handle<GraphicsBuffer>. Updated all APIs, interfaces, and implementations to use the new types, including ICommandBuffer, IResourceAllocator, ISwapChain, IRenderOutput, IRenderGraphBuilder, and related classes. Introduced TempJobAllocator for frame-latency-aware allocations. Updated ResourceHandleExtensions for new conversions. Performed minor code cleanups and removed the empty ClusterLod.cs file.

BREAKING CHANGE: All usages of Handle<Texture> and Handle<GraphicsBuffer> are replaced with Handle<GPUTexture> and Handle<GPUBuffer>. This affects all APIs and resource management code. Callers must update their code to use the new handle types.

src/Runtime/Ghost.Graphics/RenderGraphModule/RenderGraphBuilder.cs

@@ -79,6 +79,20 @@ public interface IRenderGraphBuilder : IDisposable
     /// <param name="hint">Optional hint about how the buffer will be used.</param>
     /// <returns>An identifier for the buffer.</returns>
     Identifier<RGBuffer> UseBuffer(Identifier<RGBuffer> buffer, AccessFlags accessMode);
+
+    /// <summary>
+    /// Extracts the actual texture resource associated with the given identifier for use in outside of the render graph execution context.
+    /// </summary>
+    /// <param name="texture">The identifier of the texture to be extracted.</param>
+    /// <returns>A handle to the actual texture resource that can be used outside of the render graph execution context.</returns>
+    Handle<GPUTexture> ExtractTexture(Identifier<RGTexture> texture);
+
+    /// <summary>
+    /// Extracts the actual buffer resource associated with the given identifier for use in outside of the render graph execution context.
+    /// </summary>
+    /// <param name="buffer">The identifier of the buffer to be extracted.</param>
+    /// <returns>A handle to the actual buffer resource that can be used outside of the render graph execution context.</returns>
+    Handle<GPUBuffer> ExtractBuffer(Identifier<RGBuffer> buffer);
 }
 
 public interface IRasterRenderGraphBuilder : IRenderGraphBuilder
@@ -254,6 +268,17 @@ internal class RenderGraphBuilder : IRasterRenderGraphBuilder, IComputeRenderGra
         return UseResource(buffer.AsResource(), flags, RenderGraphResourceType.Buffer).AsBuffer();
     }
 
+    // TODO: Implement ExtractTexture and ExtractBuffer to allow users to get the actual GPU resources for use outside of the render graph execution context.
+    public Handle<GPUTexture> ExtractTexture(Identifier<RGTexture> texture)
+    {
+        throw new NotImplementedException();
+    }
+
+    public Handle<GPUBuffer> ExtractBuffer(Identifier<RGBuffer> buffer)
+    {
+        throw new NotImplementedException();
+    }
+
     public Identifier<RGTexture> UseRandomAccessTexture(Identifier<RGTexture> texture)
     {
         ThrowIfDisposed();