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/containers/hashmap/clear.md

@@ -0,0 +1,34 @@
+# HashMap::Clear
+
+```cpp
+void Clear();
+```
+
+清空哈希表中的所有元素，将元素数量置为 0。桶的数量保持不变。
+
+**参数：** 无
+
+**返回：** 无
+
+**复杂度：** O(m_bucketCount)，需要清空所有桶
+
+**示例：**
+
+```cpp
+XCEngine::Containers::HashMap<int, const char*> map;
+map.Insert(1, "one");
+map.Insert(2, "two");
+map.Insert(3, "three");
+
+std::cout << "Size before clear: " << map.Size() << std::endl; // 输出 3
+
+map.Clear();
+
+std::cout << "Size after clear: " << map.Size() << std::endl; // 输出 0
+std::cout << "Empty: " << (map.Empty() ? "yes" : "no") << std::endl; // 输出 "yes"
+```
+
+## 相关文档
+
+- [HashMap 总览](hashmap.md) - 返回类总览
+- [Erase](erase.md) - 删除单个元素