[Bug]: The icon of the "Sleep" built-in action is missing while remapping buttons

### 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

0.7.4

### Operating system

Linux

### OS version & architecture

Ubuntu 26.04 LTS, GNOME Version 50, Wayland

### Device model

MX Master 3S + Logi Bolt receiver

### How is the device connected?

Logi Bolt receiver

### Affected area(s)

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

### What happened?

### Steps to reproduce

While remapping buttons on the GUI's interactive diagram: click a button hotspot — or its label card and scroll to the "Sleep" built-in action, the icon is missing.

### Diagnostics report

```markdown

```

### `openlogi list` output

```text

```

### Logs

```shell

```

### 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).

Reproduce the issue in the desktop GUI by opening the interactive diagram or button label card and selecting the Sleep built-in action. Trace how built-in actions are associated with icons, then verify that the Sleep action displays its icon while remapping buttons.

Written by the indexing model from the issue text.