Notarize and demo

Advance the notation: draft → staff_review → notarization_pending → notarized → signed. For the three-minute demo:

1. The matter ("Henderson Bungalow Purchase, buyer Virgo").
2. The template you wrote (show the markdown).
3. The notation you bound (show the rendered deed).
4. The one checklist failure you found and fixed.
5. The workflow advance to notarized.