Navigator row quick actions

Shows Duplicate and Delete buttons at the right edge of a Navigator row when you point at it or move keyboard focus onto it. From a focused row, Tab reaches the buttons and Escape returns to the row; after duplicating, focus lands on the copy, and after deleting it moves to a neighbouring row. Delete asks for a confirming second press, then offers Undo when Undo / redo element changes is on. Can also be set to sit permanently on the selected row.