DataForSEO dropped the Claude Sonnet 4.0 family from its llm_responses
catalog, so model_name=claude-sonnet-4-0 was rejected with 'Invalid
Field: model_name' while still billing the failed task. Point Claude at
claude-sonnet-4-5 and validate every model_name against DataForSEO's
accepted catalog before dispatching the paid call.
Drop the .toLowerCase() call when building the cache key's targetValue so
it matches whatever detectTarget returns. detectTarget already normalizes
domains to lowercase; keywords are passed through as-is, so lowercasing
again folded otherwise-distinct keyword queries into the same cache
entry.
