docs: update resources API docs

docs/api/resources/mesh/get-guid.md

@@ -0,0 +1,41 @@
+# Mesh::GetGUID
+
+```cpp
+ResourceGUID GetGUID() const override;
+```
+
+返回网格资源的全局唯一标识符（GUID）。GUID 在资源创建时分配，用于资源系统的唯一标识和查找。
+
+**参数：** 无
+
+**返回：** `ResourceGUID` - 资源的全局唯一标识符
+
+**异常：** 无
+
+**线程安全：** ✅
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+#include "XCEngine/Resources/Mesh.h"
+
+using namespace XCEngine::Resources;
+
+Mesh mesh;
+IResource::ConstructParams params;
+params.name = "Character_Hero";
+params.path = "assets/meshes/hero.mesh";
+params.guid = ResourceGUID::Generate(params.path);
+mesh.Initialize(params);
+
+ResourceGUID guid = mesh.GetGUID();
+if (guid.IsValid()) {
+    // GUID 有效
+}
+```
+
+## 相关文档
+
+- [类总览](mesh.md) - 返回类总览