heliosdb-nano-vector

Vector search in HeliosDB-Nano. Covers HNSW index creation (CREATE INDEX … USING HNSW), the three distance operators (<-> L2, <#> negative inner product, <=> cosine), bulk vector inserts via the library API (insert_vectors / delete_vectors / delete_vector_store), hybrid BM25 + vector search via the MCP tool, and tuning knobs in [vector] config (hnsw_ef_construction, pq_codebook_bits). Use this when the user wants…