The three pixel constants added with the #4223 fix were chosen without ever
measuring real files — CI only has synthetic split/solid fixtures, and FC
verifies nowhere else. This prints the measurements they should have been
chosen from: per pair, the hash distance, the mean drift, the changed-pixel
fraction, the verdict, and which gate produced it.
It drives the real find_similar with the real confirm rather than restating
the decision, so it cannot drift from what the importer does. Read-only:
opens files, touches no database.
Also splits fingerprint_diff out of fingerprints_match — same computation,
now returning the numbers instead of only the boolean, so the report can show
how far a pair sat from a limit rather than which side of it it fell on.
Runs inside the published :dev image (PIL + imagehash already there, no local
env needed) with the art folder mounted read-only — rule 147's channel, so
nothing has to reach main to be tried.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR
