Builds on the accounts foundation: PUT/DELETE a rating (0.5-10.0) or a
watchlist entry on any movie or series, all scoped to the bearer token's
own user, plus GET /account/ratings|watchlist/{movies,series} to list
them back. Both are polymorphic entity_type/entity_id tables, same shape
as watch_provider_offerings and trending_entries, so movie and series
share one repository/router each rather than duplicating per type.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
