A controlled system-prompt editor (value in, onChange out) with quick-pick presets composed via the OptionList primitive: selecting a preset replaces the textarea value; free-form edits that match no preset deselect all presets. Exports SYSTEM_PROMPT_PRESETS and DEFAULT_SYSTEM_PROMPT. Presentational: persistence and model wiring stay in the consumer. Feeds useChat / useGenerateText systemPrompt.
pnpm dlx shadcn@latest add "https://localmode.ai/r/ui/input-controls/system-prompt-editor.json"