Page Up doesn't move focus up in the categories grid

### What Happened?

- Navigating up and down with arrow keys works.
- Page Down works too.
- But Page Up doesn't move focus, and triggers an out-of-bounds sound (as if there was nothing to move focus to).

Enable audio and play the video:

https://github.com/user-attachments/assets/3d1e262e-6e50-4a3c-87fc-a21d0cf876be

### Steps to Reproduce

1. Move keyboard focus to the category cards on the front page.
2. Press Page Down a few times to move focus down.
3. Press Page Up to move focus up

### Expected Behavior

Page Up should move focus up, to the cards above.

### OS Version

8.x (Circe)

### OS Architecture

amd64 (on most hardwares)

### Session Type

Secure Session (Wayland, This is the default)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

_No response_