Refactor success notifications to use echo instead of toast; update selection controls and duplication logic

- Changed success notifications from `toast.success` to `echo.success` in copy, duplication, move, rotate, and selection controls.
- Updated selection logic in `PostProcessing` to use `flattenChildren` for better performance.
- Enhanced `Simulator` component to handle selected product state and execution order more effectively.
- Modified `useSelectedItem` state to include `category` and `subCategory` properties for better item classification.
- Adjusted `WallItem` interface to standardize type values and added `modelfileID` for improved asset management.

app/src/modules/scene/controls/selectionControls/copyPasteControls.tsx

@@ -415,7 +415,7 @@ const CopyPasteControls = ({ itemsGroupRef, copiedObjects, setCopiedObjects, pas
             }
         });
 
-        toast.success("Object added!");
+        echo.success("Object added!");
         clearSelection();
     };