Fix broken links in Math API docs

Fix 30+ broken cross-references in docs/api/math/:
- viewport: viewport-getaspectratio/getrect -> getaspectratio/getrect
- matrix4: ../color/operator-mul -> operator_mul, operator-index -> operator_index
- matrix4/get-*: gettranslation/getscale/getrotation -> get-translation/-scale/-rotation
- vector3 operator links: operator_*_assign -> operator-*-assign
- vector3 operator links: operator_sub/add -> operator-sub/add
- vector3 operator-eq/neq: swap mutual references to use hyphen naming
- vector4: ../plane/constructor-default -> constructor_default
- Linter fixes: aabb and rectint relative paths corrected

docs/api/math/matrix4/matrix4.md

@@ -34,7 +34,7 @@
 | [`RotationX`](rotationx.md) | 创建绕 X 轴旋转矩阵 |
 | [`RotationY`](rotationy.md) | 创建绕 Y 轴旋转矩阵 |
 | [`RotationZ`](rotationz.md) | 创建绕 Z 轴旋转矩阵 |
-| [`operator*`](operator-mul.md) | 矩阵乘法 |
+| [`operator*`](operator_mul.md) | 矩阵乘法 |
 | [`MultiplyPoint`](multiplypoint.md) | 变换点（w=1） |
 | [`MultiplyVector`](multiplyvector.md) | 变换向量（w=0） |
 | [`Transpose`](transpose.md) | 转置矩阵 |
@@ -44,7 +44,7 @@
 | [`GetRotation`](get-rotation.md) | 获取旋转分量 |
 | [`GetScale`](get-scale.md) | 获取缩放分量 |
 | [`Decompose`](decompose.md) | 分解矩阵为变换分量 |
-| [`operator[]`](operator-index.md) | 访问矩阵行数据 |
+| [`operator[]`](operator_index.md) | 访问矩阵行数据 |
 
 ## 使用示例