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/threading/task/addref.md

@@ -0,0 +1,27 @@
+# ITask::AddRef
+
+```cpp
+void AddRef()
+```
+
+增加任务的引用计数。用于延长任务的生命周期，使其不会被自动释放。
+
+**参数：** 无
+
+**返回：** 无
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+ITask* task = new MyTask();
+task->AddRef(); // 保持引用，不会在 Release 时被删除
+task->SetPriority(TaskPriority::High);
+TaskSystem::Get().Submit(std::unique_ptr<ITask>(task));
+```
+
+## 相关文档
+
+- [ITask 总览](task.md) - 返回类总览
+- [Release](release.md) - 释放引用计数