fix: Restore camera rotation and stabilize UI element scaling

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

src/Camera.h

@@ -46,6 +46,7 @@ public:
     void stopRotation();
     bool isRotating() const { return m_isRotating; }
     const QVector3D& rotationPivot() const { return m_rotationPivot; }
+    float uiCameraDistance() const;
 
     float savedXRot() const { return m_savedXRot; }
     float savedYRot() const { return m_savedYRot; }
@@ -67,6 +68,7 @@ private:
 
     QVector3D m_rotationPivot;
     bool m_isRotating = false;
+    float m_stableZoom = 0;
 
     float m_savedXRot = 0;
     float m_savedYRot = 0;