Extract drift-comparison logic out of validate-pins.ts into
validate-pins-core.ts (pure module, CLI re-exports + remains thin
orchestrator) and extract the formatter out of
redirect-decommission-report.ts into redirect-decommission-core.ts.
Add vitest coverage for both cores with baseline fixtures so
showcase-ops ProbeDrivers can reuse the same logic without forking.
Drop legacy generate-status.ts — superseded by showcase-ops live
status feed.