Supplied IDs resolve directly via a shared resolve_by_ids and never fall back to title search; metadata_providers gains per-kind ordering and a disable_metadata switch stops all automatic lookups while explicit IDs keep working.
BREAKING: --tmdb/--imdb/--tvdb are now mutually exclusive and require a usable provider; --enrich also overwrites original language; the imdbapi provider and imdb_api_enabled are replaced by a keyless imdb provider.
--enrich now sets Title.language when the service left it unset, so video tracks stop falling back to und. Adds original_language to MetadataResult (TMDB, TVDB, OMDb, IMDxAPI) and falls back to OMDb for --imdb, which previously did nothing while imdb_api_enabled defaults to false.
Document tvdb_api_key, tvdb_pin, tvdb_order and metadata_providers, the
--tvdb and --tvdb-order flags with their behaviour when an order does
not cover a whole series, the new REST API parameters, and the Matroska
TVDB2 tag prefixes.
Error messages named the resolved language for a user who only ever defaulted to orig. Audio tracks now carry is_original, resolved through Tracks.by_language so it agrees with the downloader.