To-do list rendering in kanban cards displaying wrong margins

When using markdown to-do lists in kanban cards, the checkbox is included in the list content when it should be outside. This is probably a regression that was introduced with the new icons library in `2025.9.0`.

The following markdown

```md
- [ ] Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer maximus dapibus dui, in consequat augue feugiat at.
- [] x
- [x] y
- [ ] z
- regular
- list
- items
```

produces the following list

Note

- The spacing between the checkbox and the text is different if a space is present inside the brackets (see the "x" in the example)
- Checkboxes are _inside_ the margins, aligned with the text of the regular list when they should be aligned with the markers.