Expose certifications and per-country release dates

TMDb's release_dates/content_ratings blocks were already fetched via
append_to_response but discarded at normalization -- every downstream
layer (ingestion write, repository read, schema, service) was unbuilt.
Adds the full pipeline: NormalizedReleaseDate + get_or_create_certification,
a shared polymorphic sync/read (movie and series both use it), and
MovieDetailOut/SeriesDetailOut certification + release_dates fields.

Series content_ratings has no date of its own, so each rating is anchored
to the show's first_air_date with release_type="tv".

Co-Authored-By: Claude Sonnet 5 <[email protected]>

app/services/movie_service.py

@@ -20,7 +20,14 @@ from app.schemas.movie import (
     MovieSummaryOut,
     MovieVideosOut,
 )
-from app.services.common import primary_artwork_path, split_credits, to_images_out, to_video_out
+from app.services.common import (
+    pick_certification,
+    primary_artwork_path,
+    split_credits,
+    to_images_out,
+    to_release_date_out,
+    to_video_out,
+)
 
 
 class MovieNotFoundError(Exception):
@@ -50,6 +57,7 @@ async def get_movie_detail(session: AsyncSession, movie_aurora_id: str) -> Movie
     credits_ = await polymorphic.get_credits(session, "movie", movie_id)
     artwork = await polymorphic.get_artwork(session, "movie", movie_id)
     videos = await polymorphic.get_videos(session, "movie", movie_id)
+    release_dates = await polymorphic.get_release_dates(session, "movie", movie_id)
     external_ids = await polymorphic.get_external_ids(session, "movie", movie_id)
 
     cast, crew = split_credits(credits_)
@@ -93,6 +101,7 @@ async def get_movie_detail(session: AsyncSession, movie_aurora_id: str) -> Movie
         vote_average=movie.vote_average,
         vote_count=movie.vote_count,
         adult=movie.adult,
+        certification=pick_certification(release_dates),
         genres=[GenreOut(id=aurora_id("genre", str(g.id)), name=g.name) for g in genres],
         keywords=[KeywordOut(id=aurora_id("keyword", str(k.id)), name=k.name) for k in keywords],
         cast=cast,
@@ -101,6 +110,7 @@ async def get_movie_detail(session: AsyncSession, movie_aurora_id: str) -> Movie
         collection=collection_out,
         images=to_images_out(artwork),
         videos=[to_video_out(v) for v in videos],
+        release_dates=[to_release_date_out(rd) for rd in release_dates],
         external_ids=external_ids,
         created_at=movie.created_at,
         updated_at=movie.updated_at,