Use AgentBay and $frontend-design-saas in this isolated synthetic example. Read .agents/skills/agentbay-skill-installer/SKILL.md and the named provider’s installed SKILL.md and relevant resources before work. For a large skill file, read it in bounded consecutive sections so the instructions are not lost to output truncation. The exact provider source is supplied in source-map.json; this is selected-upstream verification, not a catalogue search. All listed sources were fetched at the recorded commit and Git blob checked. Verify the installed hash against the map. Read brief.md and constitution.md. The fixture fixes scope and waives further discovery questions; never claim a real user interview or human approval. Use only this named provider skill plus AgentBay; do not auto-invoke follow-on skills. Do not delegate, access accounts, install extra dependencies, edit installed skills or checks, run downloaded companion scripts, commit or deploy. Preserve each prior stage’s files.

Use the SaaS/product UI reference to design an interactive prototype for the approved fixed brief, using docs/brief.md. Change prototype.html only; this is a disposable design prototype before final app implementation. Make it an attractive, restrained product UI with visible state progression and readable contrast. Use the supplied src/storage.js adapter via a module import, with readTasks/writeTask/clearTasks; implement prototype validation inline because final src/task.js is intentionally broken. Follow all FR-001..008. Include buttons Get started, Back, Create task (Saving… while busy), Reset demo; an input labelled Your first task; and a demo checkbox labelled Fail next save. Success has the heading Your tasks. Preserve typed text on Back and save error. Render saved titles as text, not markup. Call inspect_prototype BEFORE and AFTER edits; use its exact fixed report/screenshots and fix until it passes. Do not launch a browser from your sandbox or edit any helper, other source or test. Read the verifier if you need its exact UI contract. Keep it keyboard usable and fit 320/390/1280px.
