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/core/filewriter/Close.md

@@ -0,0 +1,40 @@
+# FileWriter::Close
+
+```cpp
+void Close();
+```
+
+关闭文件。
+
+**描述**
+
+关闭当前打开的文件。如果文件未打开，则什么都不做。析构函数会自动调用此方法。
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+#include <XCEngine/Core/FileWriter.h>
+
+using namespace XCEngine::Core;
+
+FileWriter writer;
+
+if (writer.Open("data.txt")) {
+    writer.Write("Some data\n");
+    writer.Flush();
+    writer.Close();
+}
+
+// 文件已关闭，可再次打开其他文件
+if (writer.Open("other.txt")) {
+    writer.Write("New content\n");
+}
+// 析构时自动关闭
+```
+
+## 相关文档
+
+- [FileWriter 总览](filewriter.md) - 返回类总览
+- [Open](Open.md) - 打开文件