refactor(RHI): 将窗口职责从RHI移到Platform层

- RHIDeviceDesc 删除 windowHandle/width/height/appName
- SwapChainDesc 添加 windowHandle 字段
- RHISwapChain 删除 PollEvents/ShouldClose/SetFullscreen 等窗口相关接口
- OpenGLDevice 删除 CreateRenderWindow，改用 InitializeWithExistingWindow
- 更新所有集成测试使用新API
- 273个单元测试 + 8个集成测试全部通过

engine/src/RHI/D3D12/D3D12Device.cpp

@@ -335,7 +335,7 @@ RHIFence* D3D12Device::CreateFence(const FenceDesc& desc) {
 
 RHISwapChain* D3D12Device::CreateSwapChain(const SwapChainDesc& desc) {
     auto* swapChain = new D3D12SwapChain();
-    HWND hwnd = static_cast<HWND>(m_deviceDesc.windowHandle);
+    HWND hwnd = static_cast<HWND>(desc.windowHandle);
     if (swapChain->Initialize(m_factory.Get(), m_commandQueue.Get(), hwnd,
                               desc.width, desc.height, desc.bufferCount)) {
         return swapChain;

engine/src/RHI/D3D12/D3D12SwapChain.cpp

@@ -5,8 +5,7 @@ namespace XCEngine {
 namespace RHI {
 
 D3D12SwapChain::D3D12SwapChain()
-    : m_windowHandle(nullptr)
-    , m_width(0)
+    : m_width(0)
     , m_height(0)
     , m_bufferCount(2) {
 }
@@ -40,7 +39,6 @@ bool D3D12SwapChain::Initialize(IDXGIFactory4* factory, ID3D12CommandQueue* comm
     }
 
     m_commandQueue = commandQueue;
-    m_windowHandle = windowHandle;
     m_width = width;
     m_height = height;
     m_bufferCount = bufferCount;
@@ -102,15 +100,6 @@ void D3D12SwapChain::Resize(uint32_t width, uint32_t height) {
     m_height = height;
 }
 
-void D3D12SwapChain::SetFullscreen(bool fullscreen) {
-    m_fullscreen = fullscreen;
-    m_swapChain->SetFullscreenState(fullscreen, nullptr);
-}
-
-bool D3D12SwapChain::IsFullscreen() const {
-    return m_fullscreen;
-}
-
 void* D3D12SwapChain::GetNativeHandle() {
     return reinterpret_cast<void*>(m_swapChain.Get());
 }
@@ -119,16 +108,5 @@ RHITexture* D3D12SwapChain::GetCurrentBackBuffer() {
     return &GetBackBuffer(GetCurrentBackBufferIndex());
 }
 
-bool D3D12SwapChain::ShouldClose() const {
-    return m_shouldClose;
-}
-
-void D3D12SwapChain::SetShouldClose(bool shouldClose) {
-    m_shouldClose = shouldClose;
-}
-
-void D3D12SwapChain::PollEvents() {
-}
-
 } // namespace RHI
 } // namespace XCEngine