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/vector3/lerp.md

@@ -0,0 +1,24 @@
+# Vector3::Lerp
+
+```cpp
+static Vector3 Lerp(const Vector3& a, const Vector3& b, float t)
+```
+
+在线性插值两个向量之间。参数 t 会在 [0, 1] 范围内被限制。
+
+**参数：**
+- `a` - 起始向量
+- `b` - 结束向量
+- `t` - 插值因子，0 返回 a，1 返回 b
+
+**返回：** `Vector3` - 插值结果
+
+**复杂度：** O(1)
+
+**示例：**
+
+```cpp
+Vector3 start(0.0f, 0.0f, 0.0f);
+Vector3 end(10.0f, 10.0f, 10.0f);
+Vector3 mid = Vector3::Lerp(start, end, 0.5f);  // (5.0f, 5.0f, 5.0f)
+```