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/vector2/up.md

@@ -0,0 +1,17 @@
+# Vector2::Up
+
+```cpp
+static Vector2 Up()
+```
+
+返回上方向向量 (0, 1)。
+
+**返回：** `Vector2` - 值为 (0, 1) 的向量
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+Vector2 up = Vector2::Up();
+```