[Bug]: Broken Remapping DPI Button to Middle Click

### 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

0.5.1

### Operating system

macOS

### OS version & architecture

macOS Tahoe 26.5

### Device model

MX Master 3S + Logi Bolt Receiver

### How is the device connected?

Logi Bolt 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?

When I map Middle Click button to some action A, and then map the DPI toggle button to the middle click action, the other button instead of doing the middle click action gets mapped to action A instead.

### Steps to reproduce

0. Connect and pair MX Master 3S to Mac
1. Remap Middle Click to something (ex. App Expose)
2. Remap DPI Toggle to something else (ex. Middle Click)

Then, pressing the DPI Toggle will open App Expose. Note that if you switch the DPI toggle to an unmapped action it will work for that action.

### `openlogi list` output

```text

```

### Logs

```shell

```

### macOS permissions (if applicable)

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

Start by reproducing the button-remapping flow in the GUI with an MX Master 3S and Logi Bolt receiver on macOS. Trace how the DPI Toggle action resolves a mapped Middle Click action, using the supplied reproduction steps as the behavioral check. Done means DPI Toggle performs Middle Click rather than inheriting the action assigned to the physical Middle Click button.

Written by the indexing model from the issue text.