Org contracts become obligations rather than recommendations: a three-rung
ladder (advisory/soft/hard) declared in registry data, with approval Worker
Profiles, audited override, and fail-closed evaluation at the release-gate
chokepoint. 'construct contract list' makes the enforcing set enumerable.

Also: Procedure node prefix migration restoring six silently no-op graph
checks, per-run provider budget cap, and test-isolation leak fixes.