[Bug]: Thumb wheel Volume Up / Volume Down actions do not work on Ubuntu for MX Master 2S

### Pre-flight checklist

- [x] I searched [existing issues](https://github.com/AprilNEA/OpenLogi/issues?q=is%3Aissue) and this is not a duplicate.
- [x] I am on the [latest release](https://github.com/AprilNEA/OpenLogi/releases/latest) or a recent `master` build.
- [x] I quit **Logi Options+** before running OpenLogi (the two apps fight over HID++ access and only one can own a receiver at a time).

### Which part of OpenLogi?

GUI (desktop app)

### OpenLogi version

v0.6.24

### Operating system

Linux

### OS version & architecture

Ubuntu 24.04.4 LTS

### Device model

MX Master 2S Bluetooth

### How is the device connected?

Bluetooth (direct, no receiver)

### Affected area(s)

- [ ] Device discovery / detection
- [x] Button remapping
- [ ] DPI control
- [ ] SmartShift
- [ ] Per-application profiles
- [ ] Battery status
- [ ] Settings / configuration (TOML)
- [ ] Auto-update
- [ ] Menu bar / tray
- [ ] Other

### What happened?

Hi! First of all, thanks for making OpenLogi. I recently installed it on Ubuntu and almost everything is working very well.

I found one issue with the thumb wheel / horizontal scroll wheel.

I assigned:

Thumb wheel one direction → Volume Up
Thumb wheel opposite direction → Volume Down

The assignments are saved correctly in the OpenLogi GUI, but moving the thumb wheel does not change the system volume.

Other OpenLogi functionality on the mouse appears to be working normally.

### Steps to reproduce

1. Open OpenLogi.
2.Select the Logitech mouse.
Configure the thumb wheel / horizontal scroll wheel.
Assign one direction to Volume Up.
Assign the opposite direction to Volume Down.
Save/apply the configuration.
Move the thumb wheel in either direction.

### Diagnostics report

```markdown

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### `openlogi list` output

```text

```

### Logs

```shell

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### macOS permissions (if applicable)

- [ ] OpenLogi has **Accessibility** permission (needed to remap buttons via the event tap).
- [ ] OpenLogi has **Input Monitoring** permission (needed for Bluetooth-direct devices and capture).

No source file, test, or entry point is named in the report. First reproduce the thumb-wheel Volume Up and Volume Down assignments on Ubuntu 24.04 with an MX Master 2S over Bluetooth, then trace how those actions differ from working button remaps; done means both wheel directions change system volume.

Written by the indexing model from the issue text.