Optional per-call cost-reporting callback. Real-provider rerankers (Cohere, Voyage,
OpenAI) invoke this with the actual cents charged for a single Rerank call so the
SearchEngine / scope-level budget guard can accumulate spend and short-circuit
runaway agents. NoopReRanker and BGE (local) report 0.
Optional per-call cost-reporting callback. Real-provider rerankers (Cohere, Voyage, OpenAI) invoke this with the actual cents charged for a single Rerank call so the SearchEngine / scope-level budget guard can accumulate spend and short-circuit runaway agents. NoopReRanker and BGE (local) report 0.