refactor: Revert home button color inversion logic

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

src/ViewCube.cpp

@@ -1,6 +1,5 @@
 #include "ViewCube.h"
 #include <QGuiApplication>
-#include <QImage>
 #include <QPainter>
 #include <QFont>
 #include <QOpenGLShaderProgram>
@@ -237,16 +236,7 @@ void ViewCube::paint2D(QPainter& painter, int widgetWidth, int widgetHeight)
     m_homeButtonRect = getHomeButtonRect(widgetWidth);
 
     if (m_homeButtonRenderer && m_homeButtonRenderer->isValid()) {
-        QImage image(m_homeButtonRect.size(), QImage::Format_ARGB32_Premultiplied);
-        image.fill(Qt::transparent);
-
-        QPainter imagePainter(&image);
-        m_homeButtonRenderer->render(&imagePainter);
-        imagePainter.end();
-
-        image.invertPixels(QImage::InvertRgb);
-
-        painter.drawImage(m_homeButtonRect, image);
+        m_homeButtonRenderer->render(&painter, m_homeButtonRect);
     }
 }