Add GET /collections browse endpoint; fix embedded collection poster_path

Completes browse/discover across all five entity types: movies, series,
people, companies, and now collections. No filter (no categorical field
like company_type exists for a collection) -- just page/page_size,
always alphabetical by name.

While adding poster_path to CollectionBriefOut for the browse listing,
found the same class of bug fixed earlier for company logo_path:
movie_service's embedded `collection` field never looked up its poster
artwork either, so it stayed null even after ingest_collection populated
one. Fixed alongside since it's the same schema field this feature was
already touching.

Also removed PageMeta from schemas/common.py -- scaffolding from early
spec work that was never actually wired into any endpoint; all five
browse endpoints shipped this session use a flat page/page_size/
total_results/total_pages shape instead.

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

app/services/collection_service.py

@@ -7,9 +7,10 @@ import uuid
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.ids import aurora_id, parse_aurora_id
+from app.models.collection import Collection
 from app.models.enums import ArtworkType
 from app.repositories import collection_repository, polymorphic
-from app.schemas.collection import CollectionDetailOut
+from app.schemas.collection import CollectionDetailOut, CollectionListOut
 from app.schemas.common import CollectionBriefOut
 from app.services.common import primary_artwork_path
 from app.services.movie_service import build_movie_summaries
@@ -55,13 +56,24 @@ async def get_collection_detail(
     )
 
 
+async def _collection_summary_from_row(
+    session: AsyncSession, collection: Collection
+) -> CollectionBriefOut:
+    posters = await polymorphic.get_artwork(session, "collection", collection.id, ArtworkType.POSTER)
+    return CollectionBriefOut(
+        id=aurora_id("collection", str(collection.id)),
+        name=collection.name,
+        poster_path=primary_artwork_path(posters, ArtworkType.POSTER),
+    )
+
+
 async def build_collection_summary(
     session: AsyncSession, collection_id: uuid.UUID
 ) -> CollectionBriefOut | None:
     collection = await collection_repository.get_collection_by_id(session, collection_id)
     if collection is None:
         return None
-    return CollectionBriefOut(id=aurora_id("collection", str(collection.id)), name=collection.name)
+    return await _collection_summary_from_row(session, collection)
 
 
 async def build_collection_summaries(
@@ -73,3 +85,15 @@ async def build_collection_summaries(
         if summary is not None:
             out.append(summary)
     return out
+
+
+async def list_collections(session: AsyncSession, *, page: int, page_size: int) -> CollectionListOut:
+    collections, total = await collection_repository.list_collections(
+        session, limit=page_size, offset=(page - 1) * page_size
+    )
+    results = [await _collection_summary_from_row(session, c) for c in collections]
+    total_pages = (total + page_size - 1) // page_size if total else 0
+
+    return CollectionListOut(
+        page=page, page_size=page_size, total_results=total, total_pages=total_pages, results=results
+    )

app/services/movie_service.py

@@ -54,6 +54,17 @@ async def get_movie_detail(session: AsyncSession, movie_aurora_id: str) -> Movie
 
     cast, crew = split_credits(credits_)
 
+    collection_out: CollectionBriefOut | None = None
+    if movie.collection is not None:
+        collection_posters = await polymorphic.get_artwork(
+            session, "collection", movie.collection.id, ArtworkType.POSTER
+        )
+        collection_out = CollectionBriefOut(
+            id=aurora_id("collection", str(movie.collection.id)),
+            name=movie.collection.name,
+            poster_path=primary_artwork_path(collection_posters, ArtworkType.POSTER),
+        )
+
     company_out: list[CompanyBriefOut] = []
     for company, _role in companies:
         logos = await polymorphic.get_artwork(session, "company", company.id, ArtworkType.LOGO)
@@ -87,13 +98,7 @@ async def get_movie_detail(session: AsyncSession, movie_aurora_id: str) -> Movie
         cast=cast,
         crew=crew,
         companies=company_out,
-        collection=(
-            CollectionBriefOut(
-                id=aurora_id("collection", str(movie.collection.id)), name=movie.collection.name
-            )
-            if movie.collection
-            else None
-        ),
+        collection=collection_out,
         images=to_images_out(artwork),
         videos=[to_video_out(v) for v in videos],
         external_ids=external_ids,