After the success_rate_drop fix, the SAME benign data (one Fiat VIN, "No catalog —
identified as Fiat", retried across a couple users) just moved the false positive to
unknown_vin_spike (live: "Tanınamadı 11.1%→62.5%, 5/8, critical"). A car we DID
identify but lack a catalog for is a coverage gap, not an unrecognized VIN.
- unknown_vins / unknown_vin_users now count only TRULY unrecognized VINs:
exclude identified_no_catalog=1 (the "No catalog — identified as X" case).
- Add distinct_unknown_lookups (deduped) + gate the check on ≥4 distinct
unrecognized lookups so a couple users' uncovered cars can't trip it.
Validated vs prod query_logs: all recent windows truly_unknown=0 → GATED; a real
"tanınamadı" surge (≥2 users, ≥4 distinct unrecognized VINs, rate ≥2× baseline)
still fires. typecheck clean.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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