Why: src/contracts.ts is fully regenerated from Core by make contracts;
the hand-added interface there is deleted on every sync (surfaced as a
dirty tree in the Dev composite test run).
Evidence: npx vitest run 101/101, tsc --noEmit clean, knip 42 <= 43;
Dev composite CI is authoritative.
Impact: AdminZoneSection now lives in api.ts (backend-only endpoint
type, matching existing local-type precedent); contracts.ts restored to
the generated mirror; imports updated in store and AdminZone.
Refs: WP3-I3; follows Frontend PR #63.
weichen