[Bug] ActionButton: Dropdown menu misaligned when clicking dropdown arrow

Current Behavior

In the ActionButton component, clicking the dropdown arrow opens the menu misaligned and shifted to the right.

This happens because the Popper anchors dynamically to event.currentTarget (the small arrow button) instead of the entire ButtonGroup.

Expected Behavior

The dropdown menu should always open at a consistent, aligned position under the ButtonGroup, whether the user clicks the primary button or the dropdown arrow button.

Root Cause

1. anchorEl was set to event.currentTarget inside handleToggle, which points only to the arrow button on the right edge.
2. ButtonGroup was missing a ref={anchorRef}.

Related Issue

• Meshery Issue: https://github.com/meshery/meshery/issues/21450

Environment

• Component: @sistent/sistent (src/custom/ActionButton/ActionButton.tsx)
• Consumers: Kanvas (MeshMap), Meshery UI