refactor: Introduce SketchTool base class and derived tool skeletons

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

src/RectangleTool.cpp

@@ -0,0 +1,50 @@
+#include "RectangleTool.h"
+#include "ViewportWidget.h"
+#include <QMouseEvent>
+#include <QKeyEvent>
+#include <QPainter>
+
+RectangleTool::RectangleTool(ViewportWidget* viewport)
+    : SketchTool(viewport)
+{
+}
+
+void RectangleTool::activate()
+{
+    m_isDefiningRectangle = false;
+    m_viewport->setProperty("widthInput", "");
+    m_viewport->setProperty("heightInput", "");
+    m_viewport->setProperty("dimensionEditMode", "height");
+}
+
+void RectangleTool::deactivate()
+{
+    m_isDefiningRectangle = false;
+    m_viewport->setProperty("widthInput", "");
+    m_viewport->setProperty("heightInput", "");
+}
+
+void RectangleTool::mousePressEvent(QMouseEvent *event)
+{
+    // To be implemented
+}
+
+void RectangleTool::mouseMoveEvent(QMouseEvent *event)
+{
+    // To be implemented
+}
+
+void RectangleTool::keyPressEvent(QKeyEvent *event)
+{
+    // To be implemented
+}
+
+void RectangleTool::paintGL()
+{
+    // To be implemented
+}
+
+void RectangleTool::paint2D(QPainter& painter, const QMatrix4x4& modelView, const QMatrix4x4& projection)
+{
+    // To be implemented
+}