cli-v1.6.1

Added

• Google Books provider for meta enrich — --provider google (alongside the
  default openlibrary). One request returns title/authors/publisher/date/
  categories, the ISBNs, and the edition language, so the same language-aware
  policy applies with no follow-up call. Anonymous Google Books requests share a
  small daily quota (HTTP 429 when exhausted); set GOOGLE_BOOKS_API_KEY to use
  your own key.

Changed

• CLI errors now print the full cause chain ({:#}), so the root cause is visible
  (e.g. a provider's rate limited (HTTP 429)).

Full Changelog: cli-v1.6.0...cli-v1.6.1