docs: add governance changelog

Author: LalaSkye

docs/governance/CHANGELOG.md

@@ -0,0 +1,32 @@
+# GOVERNANCE CHANGELOG
+
+Status: ACTIVE  
+Class: GOVERNANCE_CHANGELOG  
+Scope: governance-surface changes in `commit-gate-core`
+
+---
+
+## 2026-05-06 — Receipt-scope trigger class added
+
+Commits:
+- `68ac94c3` — `CHANGE_CONTROL.md`
+- `5a2a8ca4` — `docs/governance/README.md`
+- `70ba1e08` — `BUILD_RECEIPTS.md`
+
+Change:
+Receipt-scope changes are now a governed trigger class.
+
+Effect:
+A change that alters what a verification receipt is allowed to prove requires:
+
+1. a `BUILD_RECEIPTS.md` update
+2. a claim-boundary review
+3. restatement of the standing boundary
+
+Reason:
+A local verification receipt must not be silently promoted into evidence of CI success, production runtime enforcement, deployment coverage, or path-universal enforcement.
+
+Standing boundary:
+Local adversarial vector evaluation can produce durable machine-readable receipts.
+
+It does not prove production runtime enforcement or CI green proof.