Reactor audit 2026-09-23 L15: npm run version-sync runs the bumper, not the checker

[faratech]

package.json:15 maps version-sync to node scripts/update-version.js, which with no arg is a no-op that succeeds while verifying nothing; scripts/check-version-sync.py is the real checker.
Fix: point the script at python3 scripts/check-version-sync.py.

[faratech]

Fixed in 8dd1570 (npm run version-sync now runs scripts/check-version-sync.py).