fixup! feat(mingw): Add D3DX8 elimination compatibility layer (#2176)

Address PR review comments:
- Remove WWMath dependencies (Vector3/Vector4/Matrix4x4 constructors/operators)
- Make D3DXMATRIX/D3DXVECTOR types match original D3DX8 SDK exactly
- Add D3DXMATRIX operator* for matrix multiplication
- Fix D3DXShaderBuffer const correctness (const DWORD* for shader bytecode)
- Add std::min/max using declarations (replaces implicit WWMath->always.h chain)
- Convert mixed tab/space indentation to tabs
- Update comments to remove WWMath references
- Generalize D3DXCreateFont stub comment

All D3DX math functions are now self-contained inline implementations.

Author: JohnsterID