fix: Always allow camera rotation regardless of sketch plane activity

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

src/ViewportWidget.cpp

@@ -439,13 +439,11 @@ void ViewportWidget::mouseMoveEvent(QMouseEvent *event)
             m_panX += dx / 100.0f;
             m_panY -= dy / 100.0f;
         } else {
-            if (m_currentPlane == SketchPlane::NONE) {
             // Rotate
             m_xRot += 8 * dy;
             m_yRot += 8 * dx;
         }
     }
-    }
     lastPos = event->pos();
     update();
 }