//! Post-v3.0.0: only `config` survives.
//!
//! The disk-cache machinery (manifest, store, diff, file_cache, reindex)
//! was built for the doomed transformer engines and is gone. The surviving
//! ripvec engine is cacheless — `RipvecIndex` is built on first query
//! against a root and lives in process memory.
//!
//! `config` is retained because `.ripvec/config.toml` is still consulted
//! by the search engine for repo-local search settings (extension
//! whitelists, ignore globs).