Why: PR #682 merged a stale branch that reset five component pins to
pre-batch values, silently dropping the batch-1 composition on main.
Evidence: materialized byte-exact from the reviewed transport
(gatemat-run.json); regression/forward/same/skip/missing-object cases
(verify-pingate.json); make test-governance and test-pins re-run below.
Impact: new check script wired into check-pins and task-pr-check;
PIN_REGRESSION_SKIP=1 documents deliberate downgrades.
Refs: feature/audit-followups-pin-gate-m5
weichen
agent-exec-transport