Toast notification system — spring entrance, drag-to-dismiss, undo countdown, stacked
Pass details (e.g. a stack trace) — it renders behind a Details toggle. meta carries structured context for programmatic access via getToasts().
Shows a draining countdown bar. Click Undo before it expires.
Fires 4 toasts in quick succession — older ones compress behind the newest.
Fire any toast, then drag it horizontally past ~100 px (or flick) to dismiss.