Increase similar_to HNSW ef_search to improve recall

[vswamidass-sfdc]

Summary

• set SET LOCAL hnsw.ef_search = 1000 inside the similar_to controller path
• run related_by_embedding inside the same transaction so the higher HNSW search breadth applies only to this query
• keep similarity retrieval vector-based while improving recall for filtered large-library searches

Test plan

• Production console verification showed filtered vector search returns results when ef_search is raised
• No linter issues on modified controller file

Made with Cursor