Complete procedures with a way back.

Design and release a production RAG retrieval pipeline that preserves exact-term BM25 strength, adds semantic vector recall, fuses rankings with reciprocal rank fusion, reranks a bounded set, applies tenant ACLs before every branch, and proves quality, latency, cost, citation, and rollback behavior.

Govern source revisions, preserve ACLs through parsing and chunking, pin embeddings, combine lexical and semantic retrieval, validate claim-level citations, evaluate abstention, and release immutable indexes with safe rollback.