Scrollbar drag not working with ScrollablePositionedList

[MeAkhilSaji]

When using ScrollablePositionedList (v0.3.8), the scrollbar renders, but dragging the scrollbar thumb does not move the list. Scrolling only works with gestures (touch/mouse wheel).

Steps to Reproduce:

Create a ScrollablePositionedList.builder with enough items to make it scrollable.

Wrap it in a Scrollbar.

Try dragging the scrollbar thumb with a mouse.

Expected behavior:
Dragging the scrollbar thumb should scroll the list, same as it does with ListView.

Actual behavior:
Scrollbar is visible, but dragging the thumb does nothing. Only regular scroll gestures work.

Code sample:
Scrollbar( child: ScrollablePositionedList.builder( itemCount: 100, itemBuilder: (context, index) => ListTile(title: Text('Item $index')), ), );

Additional context:
The package uses ItemScrollController instead of ScrollController, which prevents Scrollbar from attaching properly. It would be great if dragging support could be added, or official guidance provided.