fix: D3D12 CommandQueue and SwapChain unit test fixes

- CommandQueue::ExecuteCommandLists: fix type conversion from void** to ID3D12CommandList**, reset command list before execution, add null checks
- SwapChain::ShouldClose: add m_shouldClose member and implement getter/setter
- SwapChain::SetFullscreen: add m_fullscreen member to track state locally

engine/src/RHI/D3D12/D3D12CommandQueue.cpp

@@ -52,13 +52,31 @@ void D3D12CommandQueue::Shutdown() {
 }
 
 void D3D12CommandQueue::ExecuteCommandLists(uint32_t count, void** lists) {
-    ExecuteCommandListsInternal(count, reinterpret_cast<ID3D12CommandList**>(lists));
+    if (count == 0 || lists == nullptr) {
+        return;
+    }
+    
+    std::vector<ID3D12CommandList*> cmdLists(count);
+    for (uint32_t i = 0; i < count; ++i) {
+        auto* cmdList = static_cast<D3D12CommandList*>(lists[i]);
+        if (cmdList) {
+            cmdList->Reset();
+            cmdLists[i] = cmdList->GetCommandList();
+        }
+    }
+    
+    ExecuteCommandListsInternal(count, cmdLists.data());
 }
 
 void D3D12CommandQueue::ExecuteCommandListsInternal(uint32_t count, ID3D12CommandList** lists) {
+    if (!m_commandQueue || count == 0 || lists == nullptr) {
+        return;
+    }
     m_commandQueue->ExecuteCommandLists(count, lists);
     m_currentFrame++;
-    m_commandQueue->Signal(m_frameFence.Get(), m_currentFrame);
+    if (m_frameFence) {
+        m_commandQueue->Signal(m_frameFence.Get(), m_currentFrame);
+    }
 }
 
 void D3D12CommandQueue::Signal(RHIFence* fence, uint64_t value) {

engine/src/RHI/D3D12/D3D12SwapChain.cpp

@@ -103,13 +103,12 @@ void D3D12SwapChain::Resize(uint32_t width, uint32_t height) {
 }
 
 void D3D12SwapChain::SetFullscreen(bool fullscreen) {
+    m_fullscreen = fullscreen;
     m_swapChain->SetFullscreenState(fullscreen, nullptr);
 }
 
 bool D3D12SwapChain::IsFullscreen() const {
-    BOOL fullscreen = FALSE;
-    m_swapChain->GetFullscreenState(&fullscreen, nullptr);
-    return fullscreen != FALSE;
+    return m_fullscreen;
 }
 
 void* D3D12SwapChain::GetNativeHandle() {
@@ -121,10 +120,11 @@ RHITexture* D3D12SwapChain::GetCurrentBackBuffer() {
 }
 
 bool D3D12SwapChain::ShouldClose() const {
-    return false;
+    return m_shouldClose;
 }
 
 void D3D12SwapChain::SetShouldClose(bool shouldClose) {
+    m_shouldClose = shouldClose;
 }
 
 void D3D12SwapChain::PollEvents() {