The user's experts, each with the opening line of its instructions

List the user's experts: each a named body of standing instructions they wrote in Roma for a kind of work (an editor, a reviewer, a coach), private to them. Returns every expert's id, name and the opening line of its instructions. Use it when the user asks which experts they have, names one, or asks for work done the way one of their experts does it; get_expert reads one in full.