A system-prompt editing surface: an autosizing monospace field with placeholder highlighting painted behind the caret, a live token estimate against a budget, presets that insert without destroying work, and an unsaved bar that owns Save and Discard.
npx shadcn@latest add @zyeon/system-prompt-editorZyeon UI limits how often it can be asked, and System Prompt Editor hasn't had its turn. Its source will show here once it has.