Data-driven recursive tree. Pass a TreeNode[] via [items] and supply an *bsTreeviewNode template to render each node body with arbitrary Angular content (icons, labels, badges, custom layout). Two-way bindings [(expandedIds)] and [(selectedIds)] let you control state.
It has no shadow root. Anything you render into it — row templates, node templates, cell renderers — stays in the document, so your app's stylesheet, your own component styles and Bootstrap's utility classes reach it normally.
Its own CSS is scoped at build time onto a data-mps attribute, the same device Angular uses for _ngcontent, so it cannot leak out onto your markup.
The trade-off runs the other way: page CSS now reaches this component's internals, exactly as emulated encapsulation behaves everywhere else. ::part() and ::slotted() no longer address it — use ordinary CSS selectors instead.