Renames 314 defs and 41 module/class-level constants. Keeps 11 names underscored where the stripped form collides in scope, plus 5.5.0 shims for the three symbols external service repos call.
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.