CAM: Fix: Show builtin shapes in separate section in shape selector

src/Mod/CAM/Path/Tool/shape/models/base.py

@@ -79,8 +79,6 @@ class ToolBitShape(Asset):
 
         self.id: str = id
 
-        self.is_builtin: bool = True
-
         self.icon: Optional[ToolBitShapeIcon] = None
 
         # Assign parameters
@@ -103,6 +101,16 @@ class ToolBitShape(Asset):
         """
         return self.id
 
+    @property
+    def is_builtin(self) -> bool:
+        """
+        Check if this shape is a built-in shape.
+
+        Returns:
+            bool: True if the shape is built-in, False otherwise.
+        """
+        return self.name.lower() == self.id
+
     @classmethod
     def _get_shape_class_from_doc(cls, doc: "FreeCAD.Document") -> Type["ToolBitShape"]:
         # Find the Body object to identify the shape type