- Add CSS rule .ws-tree-item:hover .hover-only for tree item hover visibility - Move OPEN button OUT of .actions div, place it right after title span with margin-left:auto and .hover-only class (matches Library layout exactly) - Fix renderChildren() static HTML: button now between name span and .actions - Remove duplicate button from inside .actions div - Button calls selectForPreview(node) or openSidePeek(id) for side preview panel