Grab And Move moves desktop icons when Alt + drag is used on desktop area

### Microsoft PowerToys version

0.99.1

### Installation method

Microsoft Store

### Area(s) with issue?

Grab And Move

### Steps to reproduce

1. Enable Grab And Move in PowerToys.
2. Set the activation modifier key to Alt (default behavior).
3. Go to the desktop where icons are visible.
4. Hover over an empty area of the desktop (not on a window).
5. Hold the Alt key.
6. Left-click and drag on the desktop area.

### ✔️ Expected Behavior

Grab And Move should only activate for application windows and should not interact with or move desktop icons when used on the desktop background.

### ❌ Actual Behavior

When hovering over the desktop and holding Alt + Left Click + Drag, desktop icons move unexpectedly instead of Grab And Move ignoring the desktop area. This can accidentally rearrange desktop icons.

### Upload Bug Report ZIP-file

[PowerToysReport_2026-05-22-18-08-12.zip](https://github.com/user-attachments/files/28149284/PowerToysReport_2026-05-22-18-08-12.zip)

### Additional Information

- PowerToys Grab And Move is enabled.
- Activation modifier key: Alt
- Issue occurs specifically when the mouse is over the desktop area (Explorer desktop surface).
- It seems Grab And Move may not be excluding the desktop shell/window from input handling.

### Other Software

_No response_

Start at Grab And Move's input-handling entry point and reproduce the listed Alt + left-click drag steps over the Explorer desktop surface. Trace how desktop background input is handled, then verify that dragging on empty desktop space leaves icons unchanged while window dragging still activates Grab And Move.

Written by the indexing model from the issue text.