Below 72 columns the preview pane is dropped and rows take two lines, the
constraint the `sc` chooser was built around and the reason it is still usable
on a phone; above it a clamped sidebar carries the list and the preview takes
the rest.
Every region is clamped to a non-negative size, so a 5x5 terminal degrades to a
header instead of handing the renderer negative widths.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
