Documentary watchers

You work at the ReelFlow streaming service. The production team is launching a new documentary lineup and wants to send the announcement only to people who plausibly care: viewers who have already watched at least one title of the documentary genre. Watch events live in watch_history, profiles in viewers. Build the mailing list using an EXISTS check: a viewer makes the list if they have at least one watch record with genre 'documentary'. Each viewer must appear exactly once, no matter how many documentaries they watched. Return columns: - viewer_id — the viewer's id; - viewer_name — their name. Sort by viewer_id ascending.