ZoomIt screen gets stuck shaking when scrolling to the bottom

### Microsoft PowerToys version

0.99.1

### Installation method

PowerToys auto-update

### Area(s) with issue?

ZoomIt

### Steps to reproduce

- Open the ZoomIt module
- Scroll down using a mouse wheel or down arrow key until the Attribution section appears but a few millimeters from the very bottom of the screen
- Try to scroll past that
- Notice the screen shaking vertically without scrolling down further

### ✔️ Expected Behavior

Scrolling down within the ZoomIt module should reach the very end of the window with no shaking.

### ❌ Actual Behavior

When scrolling to the bottom of the ZoomIt module, the scroll bar stops a few millimeters short of the end and trying to scroll past that will cause the screen to shake vertically for ~1 second. That happens whether scrolling with a mouse wheel or using the arrow keys.

If multiple lines are scrolled down at that point, the shaking will persist until all ~1 second shakes have concluded, e.g., scrolling 10 lines quickly will make the screen shake for ~10 seconds. During that time, trying to scroll upwards with the mouse wheel or up arrow key has no effect.

Using a mouse with a wheel that will spin freely (such as Logitech's MX Master) to quickly reach the bottom of that screen can result in it shaking for a _very_ long time.

The shaking also happens when scrolling with a trackpad, but only while the fingers are actively sliding. Sliding the fingers above a certain rate will overcome the shaking and scroll down the few remaining millimeters. If the screen is stuck shaking after scrolling with the mouse wheel or down arrow key, scrolling with the trackpad stops the shaking immediately.

I could not reproduce the issue with any other Powertoys module.

### Upload Bug Report ZIP-file

[PowerToysReport_2026-05-28-22-14-07.zip](https://github.com/user-attachments/files/28373062/PowerToysReport_2026-05-28-22-14-07.zip)

### Additional Information

Windows 10 Home
.NET SDK 8.0.417 (x86)
System Languague: English
Running as normal user or administrator

### Other Software

_No response_

The issue identifies the ZoomIt module but names no source file or test. First reproduce the bottom-of-window behavior using a mouse wheel and arrow keys, then trace the ZoomIt scrolling and boundary handling. Done means scrolling reaches the actual bottom without shaking, queued scroll input does not prolong the problem, and other input methods remain usable.

Written by the indexing model from the issue text.