docs: update TEST_SPEC.md with quad and sphere integration tests

- Add quad and sphere to integration test directory structure
- Update current integration tests table with both tests
- Update file structure section
- Bump version to 1.4

tests/RHI/D3D12/TEST_SPEC.md

@@ -110,6 +110,17 @@ integration/
 │       ├── Image/
 │       ├── Model/
 │       └── Shader/
+├── quad/                           # 矩形渲染测试
+│   ├── main.cpp
+│   ├── GT.ppm
+│   └── Res/
+│       └── Shader/
+├── sphere/                         # 球体渲染测试
+│   ├── main.cpp
+│   ├── GT.ppm
+│   └── Res/
+│       ├── Image/
+│       └── Shader/
 └── triangle/                       # 三角形渲染测试 (待实现)
     ├── main.cpp
     ├── GT_triangle.ppm
@@ -162,6 +173,8 @@ add_test(NAME D3D12_Minimal_Integration
 |--------|-------------|------|
 | D3D12_Minimal_Integration | `minimal/GT.ppm` | ✅ 通过 |
 | D3D12_RenderModel_Integration | `render_model/GT.ppm` | ❌ 待修复 |
+| D3D12_Quad_Integration | `quad/GT.ppm` | ✅ 通过 |
+| D3D12_Sphere_Integration | `sphere/GT.ppm` | ✅ 通过 |
 | D3D12_Triangle_Integration | `triangle/GT_triangle.ppm` | 🔄 待实现 |
 
 ---
@@ -266,6 +279,16 @@ tests/RHI/D3D12/
     │   ├── main.cpp                 # 有 API 问题，待修复
     │   ├── GT.ppm
     │   └── Res/
+    ├── quad/                        # 测试子文件夹
+    │   ├── main.cpp
+    │   ├── GT.ppm
+    │   └── Res/
+    ├── sphere/                      # 测试子文件夹
+    │   ├── main.cpp
+    │   ├── GT.ppm
+    │   └── Res/
+    │       ├── Image/
+    │       └── Shader/
     └── triangle/                    # 测试子文件夹 (待实现)
         ├── main.cpp
         ├── GT_triangle.ppm
@@ -300,9 +323,10 @@ engine/
 | 1.1 | 2026-03-20 | 添加 CI 集成章节，补充 Phase 5 内容 |
 | 1.2 | 2026-03-20 | 重构集成测试目录结构，每个测试独立子文件夹，stb 库移至 engine/third_party/stb/ |
 | 1.3 | 2026-03-20 | 修复 minimal GetBuffer 原生调用问题：添加 D3D12Texture 所有权语义，删除 GetSwapChain() 暴露方法，移除 gColorRTs 数组 |
+| 1.4 | 2026-03-22 | 添加 quad 和 sphere 集成测试到文档，sphere 测试包含纹理采样、深度写入等修复 |
 
 ---
 
-**规范版本**: 1.3  
+**规范版本**: 1.4  
-**最后更新**: 2026-03-20  
+**最后更新**: 2026-03-22  
 **前置文档**: [tests/TEST_SPEC.md](../TEST_SPEC.md)