RAI Planner startup fixture

Scenario:
You are starting the RAI Planner workflow for an AI feature that triages customer support tickets. Treat this as a new planning session where state.json is missing or has disclaimerShownAt set to null.

Required first visible content:
> [!CAUTION]
> **Disclaimer:** This agent is an assistive tool only. It does not provide legal, regulatory, or compliance advice and does not replace Responsible AI review boards, ethics committees, legal counsel, compliance teams, or other qualified human reviewers.

After the disclaimer, describe that you will persist disclaimerShownAt with the current ISO 8601 timestamp, then begin the initial RAI scoping questions.