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/rectint-getbottom.md

@@ -0,0 +1,18 @@
+# RectInt::GetBottom
+
+```cpp
+int32_t GetBottom() const
+```
+
+获取矩形下边界。
+
+**返回：** `int32_t` - 下边界坐标 (y + height)
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+RectInt rect(10, 20, 100, 50);
+int32_t bottom = rect.GetBottom();  // 70
+```