A fill-mask / cloze textarea that detects a configurable mask token (default [MASK]), shows an inline highlighted preview of the mask span, a 'detected' vs 'Add [MASK]' validation hint, a randomize/sample button, and a Cmd+Enter submit badge. Presentational — feeds useFillMask.
pnpm dlx shadcn@latest add "https://localmode.ai/r/ui/input-controls/mask-token-input.json"