# Phase 87: Closure And Regression Audit - Context

**Gathered:** 2026-04-11
**Status:** Implemented and verified
**Mode:** Final closure phase for `v1.51`

<domain>
## Phase Boundary

Close `v1.51` with schema-tree regression coverage and a fresh full-suite
baseline.

</domain>

<decisions>
## Implementation Decisions

### Locked decisions

- keep the closure evidence focused on contract tests and compatibility
  regressions rather than inventing a runtime acceptance script
- require a fresh full `knowledge-hub` suite baseline before closing the
  milestone

</decisions>

---

*Phase: 87-closure-and-regression-audit*
*Context captured on 2026-04-11 after Phase 87 implementation and verification*
