[BUG] Main window is not draggable on touchscreen with Avalonia UI

### Please confirm these before moving forward

- [x] I have searched for my issue and have not found a work-in-progress/duplicate/resolved issue.
- [x] I have tested that this issue has not been fixed in the latest [(beta or stable) release](https://github.com/Devolutions/UniGetUI/releases/).
- [x] I have checked the [FAQ](https://github.com/Devolutions/UniGetUI#frequently-asked-questions) section for solutions.
- [x] This issue is about a bug (if it is not, please use the [correct template](https://github.com/Devolutions/UniGetUI/issues/new/choose)).

### UniGetUI Version

2026.2.0

### Windows version, edition, and architecture

Windows 11 Pro 26200.8524

### Describe your issue

Main window is not draggable using a touch PC when Avalonia UI is enabled.
Drag to resize and flick scrolling generally work across the application on touchscreen, but moving the main window does not work.

### Steps to reproduce the issue

Using touchscreen, disable classic UI and restart.
It is not possible to move the main window around on screen using the title area without connecting a mouse.

### UniGetUI Log

```text
Log irrelevant, usability issue
```

### Package Managers Logs

```text
Package managers irrelevant
```

### Relevant information

_No response_

### Screenshots and videos

_No response_