List Redis Mistake Fares

Return top real-time mistake fares (and optionally deals) from Redis fare history.

Scans the Redis sorted sets built by live search results (fare_history:{origin}:{destination}:{cabin_class}). For each tracked route the latest observed price is scored against the median of the cached history. Routes where the latest fare is >50% below the median are classified as "mistake_fare" and always returned.

When include_deals=true, routes labeled "deal" (>30% below median) are also surfaced. This is what the marketing site's /api/deals/mistake-fares proxy requests so users see something whenever any route is meaningfully discounted, not only when there is a dramatic 50%+ outlier.

Unlike the Postgres-backed /mistake-fares endpoint, this endpoint reflects fares seen in the current search session and updates in near-real-time as users run searches.

Returns at most limit results (default 10, max 50), sorted by savings_pct descending across both labels.