[Feature]: Bind keys/shortcuts for mouse buttons

### 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

In specific apps, bound keys for mouse buttons help a lot, previously that was available in software that was originally designed for mouse use.

### Proposed solution

Add key shortcuts to buttons.

### Alternatives considered

_No response_

### Related area(s)

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

### Additional context

For Example - button forward and button back - for Page Down and Page Up

Start by tracing the existing button actions/remapping and per-application profile handling. Verify that mouse Forward and Back can be assigned to Page Down and Page Up, and confirm the mappings work in the intended applications and profiles.

Written by the indexing model from the issue text.