fix: improve doc link navigation and tree display

- Fix link resolution with proper relative/absolute path handling
- Improve link styling with underline decoration
- Hide leaf nodes from tree, only show directories
- Fix log file path for packaged app

docs/api/resources/resourcehandle/getguid.md

@@ -0,0 +1,27 @@
+# ResourceHandle::GetGUID
+
+```cpp
+ResourceGUID GetGUID() const
+```
+
+获取资源的全局唯一标识符。如果内部指针为空，则返回一个值为 0 的空 GUID。
+
+**参数：** 无
+
+**返回：** 资源的 `ResourceGUID`，如果句柄为空则返回 `ResourceGUID(0)`
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+ResourceHandle<Texture> tex = ResourceManager::Get().Load<Texture>("tex.png");
+ResourceGUID guid = tex.GetGUID();
+if (guid.IsValid()) {
+    printf("GUID: %s\n", guid.ToString().CStr());
+}
+```
+
+## 相关文档
+
+- [ResourceHandle 总览](resourcehandle.md) - 返回类总览