reui/app-shell-4
Mail and inbox shell: folder icon rail plus a wide 440px message list with live search, filter tabs, rich preview rows, and a selected-message action header (reply, star, delete). ReUI Badge, shadcn Sidebar, Tabs, Avatar, DropdownMenu.
npx get-ui-cli add reui/app-shell-4Paid component: its registry needs a licence from the library, so install it from their site.