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/tv_service.py

@@ -25,7 +25,14 @@ from app.schemas.tv import (
     SeriesSummaryOut,
     SeriesVideosOut,
 )
-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 SeriesNotFoundError(Exception):
@@ -99,6 +106,7 @@ async def get_series_detail(session: AsyncSession, series_aurora_id: str) -> Ser
     credits_ = await polymorphic.get_credits(session, "series", series_id)
     artwork = await polymorphic.get_artwork(session, "series", series_id)
     videos = await polymorphic.get_videos(session, "series", series_id)
+    release_dates = await polymorphic.get_release_dates(session, "series", series_id)
     external_ids = await polymorphic.get_external_ids(session, "series", series_id)
 
     cast, crew, creators = _split_series_credits(credits_)
@@ -122,6 +130,7 @@ async def get_series_detail(session: AsyncSession, series_aurora_id: str) -> Ser
         popularity=series.popularity,
         vote_average=series.vote_average,
         vote_count=series.vote_count,
+        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],
         creators=creators,
@@ -132,6 +141,7 @@ async def get_series_detail(session: AsyncSession, series_aurora_id: str) -> Ser
         seasons=season_briefs,
         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=series.created_at,
         updated_at=series.updated_at,