Root README covers architecture, Rust builder API quick start, YAML pipeline quick start, provider table, deno executor overview, feature flags, and testing instructions. Per-crate READMEs follow consistent structure: one-liner, what it does, quick start code example, API reference, configuration, testing, license. Engineering-confident tone throughout.
OpenSearchIndex implementing SearchIndex trait. Index mapping for workflow documents. Bool queries with multi_match for terms, term filters for status/reference, range filters for dates. Pagination support.
