Pick a language to re-render the tree. The growth direction stays vertical; only
locale.direction and locale.messages change. Node names are translated to make the
switch visible, while the search box, breadcrumb, match count, and node aria-labels come from the message
dictionary.
Localized here: search placeholder + aria-label, match-count text, breadcrumb aria-label,
root + node aria-labels (open DevTools to inspect), and full RTL mirroring for Arabic / Hebrew.
Defaults (no locale) stay English, left-to-right.