chore: snapshot editor work and restore tests

Key points:\n- restore the tests tree removed by bc47e6e\n- capture current editor workspace, scene, and docs reshuffle changes\n- keep local cloud.nvdb resources ignored from this commit

tests/RHI/D3D12/unit/test_buffer.cpp

@@ -0,0 +1,78 @@
+#include "fixtures/D3D12TestFixture.h"
+#include "XCEngine/RHI/D3D12/D3D12Buffer.h"
+#include "XCEngine/RHI/RHIEnums.h"
+
+using namespace XCEngine::RHI;
+
+TEST_F(D3D12TestFixture, Buffer_Create_DefaultHeap) {
+    BufferDesc desc = {};
+    desc.size = 1024;
+    desc.stride = 0;
+    desc.bufferType = static_cast<uint32_t>(BufferType::Vertex);
+    desc.flags = 0;
+    
+    RHIBuffer* buffer = GetDevice()->CreateBuffer(desc);
+    ASSERT_NE(buffer, nullptr);
+    
+    auto* d3d12Buffer = static_cast<D3D12Buffer*>(buffer);
+    EXPECT_EQ(d3d12Buffer->GetSize(), 1024);
+    
+    buffer->Shutdown();
+    delete buffer;
+}
+
+TEST_F(D3D12TestFixture, Buffer_Create_UploadHeap) {
+    BufferDesc desc = {};
+    desc.size = 2048;
+    desc.stride = 0;
+    desc.bufferType = static_cast<uint32_t>(BufferType::Constant);
+    desc.flags = 0;
+    
+    RHIBuffer* buffer = GetDevice()->CreateBuffer(desc);
+    ASSERT_NE(buffer, nullptr);
+    
+    buffer->Shutdown();
+    delete buffer;
+}
+
+TEST_F(D3D12TestFixture, Buffer_Get_GPUVirtualAddress) {
+    BufferDesc desc = {};
+    desc.size = 512;
+    desc.stride = 0;
+    desc.bufferType = static_cast<uint32_t>(BufferType::Vertex);
+    desc.flags = 0;
+    
+    RHIBuffer* buffer = GetDevice()->CreateBuffer(desc);
+    ASSERT_NE(buffer, nullptr);
+    
+    auto* d3d12Buffer = static_cast<D3D12Buffer*>(buffer);
+    EXPECT_NE(d3d12Buffer->GetGPUAddress(), 0);
+    
+    buffer->Shutdown();
+    delete buffer;
+}
+
+TEST_F(D3D12TestFixture, Buffer_Map_Unmap) {
+    BufferDesc desc = {};
+    desc.size = 256;
+    desc.stride = 0;
+    desc.bufferType = static_cast<uint32_t>(BufferType::Constant);
+    desc.flags = 0;
+    
+    RHIBuffer* buffer = GetDevice()->CreateBuffer(desc);
+    ASSERT_NE(buffer, nullptr);
+    
+    void* mappedData = buffer->Map();
+    ASSERT_NE(mappedData, nullptr);
+    
+    memset(mappedData, 0xAB, 256);
+    
+    buffer->Unmap();
+    
+    buffer->Shutdown();
+    delete buffer;
+}
+
+TEST_F(D3D12TestFixture, Buffer_Get_AlignmentRequirements) {
+    EXPECT_GE(256 % 256, 0);
+}