SortableJS/Vue.Draggable ? reverse-engineered prompt

Build me a Vue 2 drag and drop component that keeps a list in sync with the UI, so I can reorder items with the mouse or touch and have the underlying array update automatically.

I want it to work like a normal draggable wrapper around a v-for list, with support for dragging between lists, drag handles, canceling a move, and a clone mode for copied items. It should also play nicely with transition groups and with existing component libraries when I pass a custom tag or component.

Please include a simple demo page, good examples for common use cases, and tests for the main behaviors. If you need to check current Vue or Sortable docs online while wiring it up, go ahead. Keep the API easy to use, and make sure the component feels polished and ready to publish.