[Bug] Middle-click autoscroll in sidebar scrolls the main document instead #1654

What happened?

Description

Middle-click autoscroll does not target the sidebar's own scrollable area.

In the Annotations panel and Ask AI chat, normal mouse-wheel scrolling works correctly. But when middle-click autoscroll is started inside the sidebar, moving the pointer up or down scrolls the main document view instead.

So the expectation would be: Middle-click autoscroll should target the scrollable container in which it was initiated:

• middle-click in the main document → scroll the document;
• middle-click in the sidebar → scroll the sidebar.

Steps to reproduce

1. Open a Plan Review / Annotate session with a scrollable main document.
2. Open the Annotations panel or Ask AI sidebar and make sure it is also vertically scrollable.
3. Hover the sidebar and scroll with the mouse wheel - the sidebar scrolls correctly.
4. Middle-click inside the sidebar to activate autoscroll.
5. Move the pointer vertically.

Additional context

#1647 / #1648 addressed a related but separate scroll-target issue for keyboard scrolling; this report concerns middle-click autoscroll only.

Thanks for reading and considering this (again)!

Plannotator version

plannotator 0.27.19

OS

Windows

Agent

Claude Code

Where did it happen?

Plan review