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/string/trim.md

@@ -0,0 +1,35 @@
+# String::Trim
+
+```cpp
+String Trim() const;
+```
+
+移除字符串两端的空白字符（空格、制表符、换行符、回车符），返回一个新的 String 对象，原字符串不变。
+
+**参数：** 无
+
+**返回：** 去除两端空白后的新 String 对象
+
+**复杂度：** O(n)，其中 n 为字符串长度
+
+**示例：**
+```cpp
+#include "XCEngine/Containers/String.h"
+#include <iostream>
+
+int main() {
+    XCEngine::Containers::String s("   Hello World   ");
+
+    XCEngine::Containers::String trimmed = s.Trim();
+    std::cout << "\"" << trimmed.CStr() << "\"" << std::endl;  // 输出: "Hello World"
+
+    XCEngine::Containers::String s2("\t\n  test  \t\n");
+    std::cout << "\"" << s2.Trim().CStr() << "\"" << std::endl;  // 输出: "test" (空格、制表符、换行、回车被移除)
+
+    return 0;
+}
+```
+
+## 相关文档
+
+- [String 总览](string.md) - 返回类总览