[BUG] Linux launcher shell script is pointing at a nonexistent executable

### 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

2026.2.2

### Windows version, edition, and architecture

Bazzite Linux 44, x64

### Describe your issue

The shell script used to launch UniGetUI on Linux (`/usr/bin/unigetui`) seems to be referencing an out of date executable name:

```
#!/bin/sh
exec /opt/unigetui/UniGetUI.Avalonia "$@"
```

However the executable is now called `/opt/unigetui/UniGetUI`, so this script fails to launch the app.

### Steps to reproduce the issue

1. Open a terminal on Linux
2. Run this command: `unigetui`

### UniGetUI Log

```text
N/A
```

### Package Managers Logs

```text
N/A
```

### Relevant information

_No response_

### Screenshots and videos

_No response_

Start by locating the packaging source for /usr/bin/unigetui and compare its target with the installed executable under /opt/unigetui. Run unigetui on Linux to verify the launcher starts successfully and no longer references the nonexistent name.

Written by the indexing model from the issue text.