Add the shared parent | current | preview row primitive that implements
yazi's mgr.ratio = [1, 3, 3] contract via Yoga flexGrow, so every list
tab renders an identical, layout-stable shell regardless of terminal
size.
- New YaziPaneRow component: three bordered columns grow at 1/7 : 3/7
: 3/7 with flexBasis=0 (content can never stretch its slot). The
current column carries the accent focus ring when `focused` is
truthy; parent and preview stay muted. The blank parent keeps its
1/7 slot with a muted placeholder rather than collapsing.
- PANE_RATIO.current 4 -> 3 to match yazi's [1, 3, 3].
- Add render-based tests covering the 1:3:3 ratios (incl. null
parent/preview) and the focused/unfocused accent ring behavior.
- Configure the bun test preload for the solid JSX transform.
