[Feature]: Long press (maintain) instead of continuous clicking

### Pre-flight checklist

- [x] I searched existing issues and the [Roadmap](https://github.com/AprilNEA/OpenLogi#roadmap), and this isn't already tracked.

### Problem / motivation

I assigned some buttons on my MX Master 2S to do some actions, like volume up/down. The thing is that I cannot use long pressing (maintain) so the volume moves up or down while pressing. Instead, I have to continuously clicking to increase/decrease volumen.

### Proposed solution

It would be great if it would support long pressing so the action is executed while the button is pressed.

### Alternatives considered

_No response_

### Related area(s)

- [ ] GUI
- [ ] CLI
- [x] Button actions / remapping
- [ ] DPI
- [ ] SmartShift
- [ ] Per-application profiles
- [ ] Configuration (TOML)
- [ ] Auto-update
- [ ] Other

### Additional context

_No response_

No file or test is named. Start by tracing the button actions/remapping entry point and how button presses are currently dispatched, then determine how a press can remain active until release. Done means a mapped action supports long pressing, including volume changes, without requiring repeated clicks; add or update coverage for press and release behavior.

Written by the indexing model from the issue text.