refactor: 将 tests/D3D12 的 CommandList 替换为 D3D12CommandList 类

- 将全局 ID3D12GraphicsCommandList 替换为 D3D12CommandList
- 更新初始化、Reset、Close 调用
- 修复 Initialize 中不应调用 Close() 的问题
- 测试通过，截图与 GT.ppm 完全匹配

tests/D3D12/main.cpp

@@ -17,6 +17,7 @@
 #include "XCEngine/RHI/D3D12/D3D12Device.h"
 #include "XCEngine/RHI/D3D12/D3D12CommandQueue.h"
 #include "XCEngine/RHI/D3D12/D3D12CommandAllocator.h"
+#include "XCEngine/RHI/D3D12/D3D12CommandList.h"
 #include "XCEngine/RHI/D3D12/D3D12Fence.h"
 #include "XCEngine/RHI/D3D12/D3D12Screenshot.h"
 #include "XCEngine/Debug/Logger.h"
@@ -61,7 +62,7 @@ UINT gDSVDescriptorSize = 0;
 
 // 命令相关
 XCEngine::RHI::D3D12CommandAllocator gCommandAllocator;
-ID3D12GraphicsCommandList* gCommandList = nullptr;
+XCEngine::RHI::D3D12CommandList gCommandList;
 
 // 同步对象
 XCEngine::RHI::D3D12Fence gFence;
@@ -660,7 +661,7 @@ bool InitD3D12(HWND inHWND, int inWidth, int inHeight) {
 	device->CreateDepthStencilView(gDSRT, &d3dDSViewDesc, gSwapChainDSVHeap->GetCPUDescriptorHandleForHeapStart());
 
 	gCommandAllocator.Initialize(device, XCEngine::RHI::CommandQueueType::Direct);
-	device->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, gCommandAllocator.GetCommandAllocator(), nullptr, IID_PPV_ARGS(&gCommandList));
+	gCommandList.Initialize(device, XCEngine::RHI::CommandQueueType::Direct, gCommandAllocator.GetCommandAllocator());
 
 	gFence.Initialize(device, 0);
 
@@ -675,7 +676,7 @@ ID3D12CommandAllocator* GetCommandAllocator() {
 }
 
 ID3D12GraphicsCommandList* GetCommandList() {
-	return gCommandList;
+	return gCommandList.GetCommandList();
 }
 
 void WaitForCompletionOfCommandList() {
@@ -694,8 +695,8 @@ void WaitForCompletionOfCommandList() {
 // 关闭CommandList → ExecuteCommandLists → Signal Fence
 //=================================================================================
 void EndCommandList() {
-	gCommandList->Close();
-	ID3D12CommandList* ppCommandLists[] = { gCommandList };
+	gCommandList.Close();
+	ID3D12CommandList* ppCommandLists[] = { gCommandList.GetCommandList() };
 	gCommandQueue.ExecuteCommandLists(1, ppCommandLists);
 	gFenceValue += 1;
 	gCommandQueue.Signal(gFence.GetFence(), gFenceValue);
@@ -942,7 +943,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
 			float timeSinceAppStartInSecond = float(timeSinceAppStartInMS) / 1000.0f;
 			color[0] = timeSinceAppStartInSecond;
 			commandAllocator->Reset();
-			commandList->Reset(commandAllocator, nullptr);
+			gCommandList.Reset(gCommandAllocator.GetCommandAllocator());
 			BeginRenderToSwapChain(commandList);
 			commandList->SetPipelineState(pso);
 			commandList->SetGraphicsRootSignature(rootSignature);