Author personas and journey flows

For: Spec Author

Part of: User Docs Composition (Personas & Journeys)

Steps

• Add (spec) — personas[] to system.usm (id, name, description)
• Annotate (spec) — flows with actor (flow-level or per-step) and optional surface, marking them as journeys
• The system validates — schema: persona ids referenced by actor exist; unknown actors rejected (hard error in generate pass)
• Review (browser) — composed user docs rendered live via usm docs serve