Builds Meilisearch /indexes/:uid/search JSON bodies from Scrypath.Query.

When both filter and facetFilters are present, Meilisearch combines them with AND semantics (see Meilisearch search parameters — filter + facetFilters).

Ranking score knobs (rankingScoreThreshold, showRankingScore, showRankingScoreDetails) are taken from query.per_query when present. Boolean flags are omitted when false to keep payloads minimal.