S1: skill recipe now says result score is merged rank. Also send
non-zero --min-score to the server (N1), sort include_domains (N2),
and note that search_queries counts each sub-query (N3).
Native include/exclude domains, time_range, topic, exact_match, min_score,
and up to 4 queries fused with RRF. Honesty notes stay off the Warn/fail
path. Tavily keeps include_answer false and sets auto_parameters false.
Cache key is canonical JSON. CLI flags and skill recipe included.