Design partner onboarding runbook — step-by-step guide for enterprise pilot deployment

Internal runbook for taking a design partner from intro call to production pilot.

**Acceptance:**
- [ ] Day 0: intro call → questionnaire
- [ ] Day 1-7: environment assessment
- [ ] Day 8-14: install + initial workload
- [ ] Day 15-30: feedback iteration
- [ ] Day 30-90: production rollout