An always-visible pill in the top-right corner of every node showing a number — a descendant
count, a direct-child count, or any per-node metric you supply. Enable with
countBadgeEnabled: true and pick the number via countBadgeSource.
Each department shows how many direct children it has. Root and leaves show none.
Every node shows its total descendant count across all levels.
Reads a per-node count field — any metric, not a structural count.
Emerald badge; hidden on nodes with fewer than 2 descendants.
Arabic labels with locale.direction: 'rtl'. The tree mirrors right-to-left and each badge moves to
the node's top-left corner.