Bulk-ingest embeddings: { items: [{entityName, embedding, model?}, ...] }.
Each item is upserted independently; per-item failures are reported rather
than aborting the batch — the shape RAG ingestion pipelines expect.
Example-based recommendation: build a query from positive (and optional
negative) example entities and search. { positive: [names], negative?: [names], topK?, entityType? }. The example entities are excluded from results.