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/math/rect/getcenter.md

@@ -0,0 +1,18 @@
+# Rect::GetCenter
+
+```cpp
+Vector2 GetCenter() const
+```
+
+获取矩形中心点。
+
+**返回：** `Vector2` - 中心点坐标
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+Rect rect(10.0f, 20.0f, 100.0f, 50.0f);
+Vector2 center = rect.GetCenter();  // (60.0f, 45.0f)
+```