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/resourcemanager/unload.md

@@ -0,0 +1,31 @@
+# ResourceManager::Unload
+
+```cpp
+void Unload(const Containers::String& path)
+void Unload(ResourceGUID guid)
+```
+
+卸载指定资源。按路径或 GUID 查找资源，如果引用计数降至零则释放资源内存。
+
+**参数：**
+- `path` - 资源路径
+- `guid` - 资源全局唯一标识符
+
+**返回：** 无
+
+**复杂度：** O(1) 查找
+
+**示例：**
+
+```cpp
+// 按路径卸载
+ResourceManager::Get().Unload("textures/player.png");
+
+// 按 GUID 卸载
+ResourceGUID guid = tex.GetGUID();
+ResourceManager::Get().Unload(guid);
+```
+
+## 相关文档
+
+- [ResourceManager 总览](resourcemanager.md) - 返回类总览