Add movie/series ratings and watchlist

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]>

app/schemas/movie.py

@@ -106,3 +106,15 @@ class MovieListOut(BaseModel):
     total_results: int
     total_pages: int
     results: list[MovieSummaryOut] = []
+
+
+class RatedMovieOut(MovieSummaryOut):
+    rating: float
+
+
+class RatedMovieListOut(BaseModel):
+    page: int
+    page_size: int
+    total_results: int
+    total_pages: int
+    results: list[RatedMovieOut] = []