Journal name abbreviation lookup — ISO 4 + MEDLINE, multi-source cascade (JabRef ~25K journals → AbbrevISO → NLM Catalog), BibTeX field rewrite, batch and NDJSON streaming, agent-native JSON envelope with stable error codes, dry-run on every mutating command, --idempotency-key for replay-safe bib rewrites, and atomic cache rebuild that preserves the old cache on failure