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/try-lock.md

@@ -0,0 +1,32 @@
+# SpinLock::try_lock
+
+```cpp
+bool try_lock()
+```
+
+STL 兼容的 `try_lock()` 方法，与 [`TryLock`](trylock.md) 等效。满足 STL `Lockable` 概念要求。
+
+**参数：** 无
+
+**返回：** `bool` - 获取成功返回 true，锁不可用返回 false
+
+**复杂度：** O(1)
+
+**线程安全：** ✅
+
+**示例：**
+
+```cpp
+Threading::SpinLock spinLock;
+
+void STLCompatibleTry() {
+    if (spinLock.try_lock()) {
+        // 临界区操作
+        spinLock.unlock();
+    }
+}
+```
+
+## 相关文档
+
+- [SpinLock 总览](spinlock.md) - 返回类总览