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/mutex/unlock.md

@@ -0,0 +1,32 @@
+# Mutex::Unlock
+
+```cpp
+void Unlock()
+```
+
+释放互斥锁，允许其他等待中的线程获取该锁。
+
+**参数：** 无
+
+**返回：** 无
+
+**复杂度：** O(1)
+
+**注意：** 必须在持有锁的线程中调用 Unlock。解锁一个未持有的锁将导致未定义行为。
+
+**示例：**
+
+```cpp
+Threading::Mutex mtx;
+std::vector<int> data;
+
+void SafePush(int value) {
+    mtx.Lock();
+    data.push_back(value);
+    mtx.Unlock();
+}
+```
+
+## 相关文档
+
+- [Mutex 总览](mutex.md) - 返回类总览