StarterCategories

Starter questions grouped by category for an empty chat. The category row is a group of buttons with aria-pressed that control the list under it; the starters are Suggestions chips. The first category is picked by default (defaultValue={null} starts with none); pass value and onChange to control it. Put it in emptyState.content of AgentChat, which renders host content under the greeting in both the welcome and center layouts, and fill the composer with the picked starter through draft.