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/tv.py

@@ -115,6 +115,18 @@ class SeriesListOut(BaseModel):
     results: list[SeriesSummaryOut] = []
 
 
+class RatedSeriesOut(SeriesSummaryOut):
+    rating: float
+
+
+class RatedSeriesListOut(BaseModel):
+    page: int
+    page_size: int
+    total_results: int
+    total_pages: int
+    results: list[RatedSeriesOut] = []
+
+
 class EpisodeBriefOut(BaseModel):
     id: str
     episode_number: int