refactor: improve test infrastructure and fix OpenGL GLAD initialization

- Rename D3D12Enum.h to D3D12Enums.h for naming consistency
- Fix OpenGL unit test GLAD initialization by using gladLoadGL()
  instead of gladLoadGLLoader(wglGetProcAddress) for fallback support
- Migrate remaining tests to use gtest_discover_tests for granular
  test discovery (math, core, containers, memory, threading, debug,
  components, scene, resources, input, opengl)
- Remove obsolete TEST_RESOURCES_DIR and copy_directory commands
  from OpenGL unit test CMakeLists (minimal/Res doesn't exist)
- Update TEST_SPEC.md with performance metrics and per-module
  build/test commands for faster development workflow
- Update CMake path references to use lowercase paths

docs/api/threading/spinlock/lock-stl.md

@@ -0,0 +1,31 @@
+# SpinLock::lock
+
+```cpp
+void lock()
+```
+
+STL 兼容的 `lock()` 方法，与 [`Lock`](lock.md) 等效。满足 STL `Lockable` 概念要求。
+
+**参数：** 无
+
+**返回：** 无
+
+**复杂度：** 平均 O(1)，最坏情况取决于竞争程度
+
+**线程安全：** ✅
+
+**示例：**
+
+```cpp
+Threading::SpinLock spinLock;
+
+void STLCompatibleUsage() {
+    spinLock.lock();
+    // 临界区操作
+    spinLock.unlock();
+}
+```
+
+## 相关文档
+
+- [SpinLock 总览](spinlock.md) - 返回类总览