A store whose id still matches the local registry is not compared, so the patched store changes
the id and Int64 together, as a real shape change does. Presence threshold set to the measured
174 required slots. goldens/README.md is the base file plus the nil-vector section (the earlier
commit rewrote its line endings).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>