feat: 实现 D3D12Shader 着色器类

- 添加 D3D12Shader.h/cpp
- 支持从文件编译着色器
- 支持从内存编译着色器
- 测试通过

engine/include/XCEngine/RHI/D3D12/D3D12Shader.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <d3d12.h>
+#include <wrl/client.h>
+#include <string>
+
+#include "D3D12Enum.h"
+
+using Microsoft::WRL::ComPtr;
+
+namespace XCEngine {
+namespace RHI {
+
+class D3D12Shader {
+public:
+    D3D12Shader();
+    ~D3D12Shader();
+
+    bool CompileFromFile(const wchar_t* filePath, const char* entryPoint, const char* target);
+    bool Compile(const void* sourceData, size_t sourceSize, const char* entryPoint, const char* target);
+    void Shutdown();
+
+    const D3D12_SHADER_BYTECODE GetBytecode() const;
+    ShaderType GetType() const { return m_type; }
+
+private:
+    ComPtr<ID3DBlob> m_bytecode;
+    ComPtr<ID3DBlob> m_error;
+    ShaderType m_type;
+};
+
+} // namespace RHI
+} // namespace XCEngine