Harness benchmark / 2026-11-04

Main prompt

Build a polished, responsive grocery list web app. Work only in /home/user/grocery-trial (or the backend project directory if that absolute path is unavailable). The sole starting file is README.md with these exact contents:
# Grocery list trial

Starting point: empty app. Implement according to the trial prompt.

If the backend does not have that file, create it verbatim before implementing. Do not use unrelated existing project files.
Requirements: add grocery items with name, quantity and category; edit and delete items; mark purchased/unpurchased; filter all/remaining/purchased; search; clear purchased; show remaining count; persist everything in localStorage. Include useful initial sample groceries only on first load. Make an attractive, accessible mobile and desktop UI with keyboard-friendly controls and empty states. Use a simple self-contained frontend stack of your choice, no external paid services or API keys. Test core flows and run build/tests as appropriate. Do not delegate to other agents or invoke additional AI.
Launch an app preview as a detached process (nohup setsid), listening on 0.0.0.0. On Boat use host <port> --public, adding --localhost only if loopback-bound. Verify the public token-free HTTPS URL responds. On hosted backends use their available preview mechanism; if Boat hosting is unavailable explain this and return the native public preview if possible. Never expose unrelated services.
Return a concise summary with implemented features, tests and their outcomes, preview URL, project path, and limitations. Do not stop the preview server.