REST search swaps the semantic and keyword result limits

DefaultSearchResource.search passes limitKeywordResults into hybridSearch's limitSemanticSimilarity parameter and limitSemanticResults into limitKeywordSearch — swapped since the hybrid search was introduced (LLMAI-130). Both limits default to the same value, so it only manifests when a REST caller sets asymmetric limits: their keyword budget then silently drives the KNN topK and vice versa. The MCP tool and the chat filter pass theirs correctly.