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/debug/logcategory/logcategorytostring.md

@@ -0,0 +1,28 @@
+# LogCategoryToString
+
+```cpp
+const char* LogCategoryToString(LogCategory category)
+```
+
+将 `LogCategory` 枚举值转换为可读字符串。
+
+**参数：**
+- `category` - 日志分类
+
+**返回：** 对应分类的字符串（"General", "Rendering", "Physics" 等）
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+#include <XCEngine/Debug/LogCategory.h>
+
+XCEngine::Debug::LogCategory cat = XCEngine::Debug::LogCategory::Rendering;
+const char* str = XCEngine::Debug::LogCategoryToString(cat);
+// str == "Rendering"
+```
+
+## 相关文档
+
+- [LogCategory 总览](logcategory.md) - 返回类总览