Add unit tests for TUI

### Is your feature request related to a problem?

_No response_

### Describe the solution you'd like

Use a test library like https://github.com/knz/catwalk to add some unit tests to the TUI

### Additional context

_No response_

### Epic

_No response_

Start by locating the TUI implementation and its existing test setup; the issue does not name specific files or entry points. Review the catwalk library to determine how it can exercise the TUI, then add unit tests covering the intended TUI behavior. Done means the tests run successfully and provide coverage for the TUI.

Written by the indexing model from the issue text.