PR #416 introduced pr_work_lease reviewer blocks and mandatory full
40-hex expected_head_sha on mark/merge paths. Update audit, review,
permission-report, terminal hard-stop, inventory, and schema tests to
patch lease comment fetches, seed ready review decisions, and use
consistent HEAD_SHA constants so the full suite passes again.
Merge current prgs/master into feat/issue-399-conflict-fix-leases.
Preserve reviewer PR lease gate (#407) before conflict-fix stale-head
gate (#399); document both as §26B and §26C. Align MCP and validator
tests with mandatory expected_head_sha and stale-head proof fields.