refactor: Implement Rectangle tool with snapping and dimensions

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

src/SketchRectangle.cpp

@@ -0,0 +1,61 @@
+#include "SketchRectangle.h"
+#include <QJsonArray>
+
+namespace
+{
+    void pointToJson(const gp_Pnt& p, QJsonArray& arr)
+    {
+        arr.append(p.X());
+        arr.append(p.Y());
+        arr.append(p.Z());
+    }
+
+    gp_Pnt jsonToPoint(const QJsonArray& arr)
+    {
+        return gp_Pnt(arr[0].toDouble(), arr[1].toDouble(), arr[2].toDouble());
+    }
+}
+
+SketchRectangle::SketchRectangle()
+{
+}
+
+SketchRectangle::SketchRectangle(const gp_Pnt& corner1, const gp_Pnt& corner2)
+    : m_corner1(corner1), m_corner2(corner2)
+{
+}
+
+SketchObject::ObjectType SketchRectangle::type() const
+{
+    return ObjectType::Rectangle;
+}
+
+void SketchRectangle::read(const QJsonObject& json)
+{
+    if (json.contains("corner1") && json["corner1"].isArray()) {
+        m_corner1 = jsonToPoint(json["corner1"].toArray());
+    }
+    if (json.contains("corner2") && json["corner2"].isArray()) {
+        m_corner2 = jsonToPoint(json["corner2"].toArray());
+    }
+}
+
+void SketchRectangle::write(QJsonObject& json) const
+{
+    json["type"] = "Rectangle";
+    QJsonArray c1, c2;
+    pointToJson(m_corner1, c1);
+    pointToJson(m_corner2, c2);
+    json["corner1"] = c1;
+    json["corner2"] = c2;
+}
+
+const gp_Pnt& SketchRectangle::corner1() const
+{
+    return m_corner1;
+}
+
+const gp_Pnt& SketchRectangle::corner2() const
+{
+    return m_corner2;
+}