pgEdge RAG Server shared keyword index leaked results between concurrent unauthenticated requests

pgEdge RAG Server is an API server for retrieval-augmented generation over PostgreSQL content using pgvector. Prior to 2.0.0, the BM25 keyword index is a single per-pipeline object shared by the unauthenticated query endpoint, and concurrent requests lock its clear, refill, and search operations separately. This allows one request to search a corpus populated through another request's search filter, which can return documents belonging to a different tenant or customer without malformed input. The affected responses cannot be identified retrospectively from the server logs. This issue is fixed in version 2.0.0.