Region Sidebar fails to auto‑scroll when selecting rectangles in image

**Describe the bug**
When a rectangle is selected on the image, the corresponding region in the Region Sidebar gets selected but remains invisible — the sidebar does not automatically scroll to display the target element.

**To Reproduce**

1. Use the standard OCR template.
2. Create approximately 30 rectangles (exceeding the visible area of the sidebar).
3. Select the ~fifth rectangle on the image — its corresponding region is properly displayed and selected in the sidebar.
4. Select the ~twenty‑fifth rectangle on the image — the corresponding region is not visible in the sidebar (the sidebar fails to scroll to show it).

**Expected behavior**
Upon selecting a rectangle on the image (or an item in the info sidebar), the Region Sidebar should:
1. Automatically scroll to the related region;
2. Display it in the visible area;
3. Keep it selected.

**Actual Behavior**
The selected region remains outside the visible area of the sidebar — manual scrolling is required to locate it.

**Screenshots**
Not required (behavior is reproducible via steps above).

**Environment:**
- OS: Ubuntu 22.04
- Browser: Firefox (latest version)
- Label Studio Version: Docker (latest) UI 1.21.0

**Additional context**
This issue is particularly problematic when working with OCR tasks containing ~100 text blocks on a single image. The current behavior forces users to manually scroll the Region Sidebar back and forth to locate specific regions, significantly reducing workflow efficiency.