Finalize digital-twin scope as two ACL-based patterns

Plan's digital-twin scope is now exactly (1) environment-lifecycle
promotion via ACL flip on write authority and (2) safe read-only
consumption for KPI / monitoring systems — both delivered by
already-committed architecture. Removes the meeting-prep brief and the
management-delivered use-cases source document; canonical model and
state vocabulary stand as pillar-2 work on their own.

CLAUDE.md

@@ -16,7 +16,6 @@ Plan content lives in markdown files at the repo root to keep it easy to read an
 ### Component detail files
 
 - [`current-state/legacy-integrations.md`](current-state/legacy-integrations.md) — authoritative inventory of **bespoke IT↔OT integrations** that cross ScadaBridge-central outside ScadaBridge. Denominator for pillar 3 retirement.
-- [`goal-state/digital-twin-management-brief.md`](goal-state/digital-twin-management-brief.md) — meeting-prep artifact for the management conversation that turns "we want digital twins" into a scoped response. Parallel structure to `goal-state.md` → Strategic Considerations → Digital twin.
 - [`schemas/`](schemas/) — **Canonical OT equipment definitions seed** (temporary location — see `schemas/README.md`). JSON Schema format definitions, FANUC CNC pilot equipment class, UNS subtree example, and documentation. Contributed by the OtOpcUa team; ownership TBD. To be migrated to a dedicated `schemas` repo once created.
 
 ### Output generation pipeline