Disclosure in shared/ui, imported as `import * as Disclosure`, is a native <details> that unfolds as it opens: a Root, a Summary without the browser's marker, and a Chevron that turns as its own disclosure opens, not one around it, pointing toward the end of the line or, with points="down", down. The sidebar's tags, a reply's sources, the Why? on a pending reply, and the steps block, thoughts, and tool steps use it in place of hand-built details, so the tags now unfold as the rest do. The step and tag chevrons no longer flip twice right to left, where they pointed the wrong way closed and up when open.