feat: Implement circle drawing tool

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

src/ApplicationController.cpp

@@ -3,6 +3,7 @@
 #include "SketchFeature.h"
 #include "SketchLine.h"
 #include "SketchRectangle.h"
+#include "SketchCircle.h"
 #include "MainWindow.h"
 
 #include <QInputDialog>
@@ -148,6 +149,13 @@ void ApplicationController::addRectangle(const gp_Pnt& corner1, const gp_Pnt& co
     }
 }
 
+void ApplicationController::addCircle(const gp_Pnt& center, double radius)
+{
+    if (m_activeSketch) {
+        m_activeSketch->addObject(new SketchCircle(center, radius));
+    }
+}
+
 void ApplicationController::endSketch()
 {
     m_activeSketch = nullptr;