revert: remove manual serialization to fix crash

backend/routers/shows.py

@@ -109,25 +109,8 @@ def read_shows(
     
     shows = session.exec(query.offset(offset).limit(limit)).all()
     
-    # Manual population to ensure relationships are serialized
-    # (Pydantic v2/SQLModel can be tricky with ORM relationships sometimes)
-    response_shows = []
-    for show in shows:
-        # Convert ORM object to ShowRead explicitly
-        # We use model_validate to get base fields, then set relationships
-        s_read = ShowRead.model_validate(show)
-        
-        if show.vertical:
-            s_read.vertical = VerticalSimple.model_validate(show.vertical)
-        if show.venue:
-            s_read.venue = VenueRead.model_validate(show.venue)
-        if show.tour:
-            s_read.tour = TourRead.model_validate(show.tour)
-            
-        response_shows.append(s_read)
-    
     return PaginatedResponse(
-        data=response_shows,
+        data=shows,
         meta=PaginationMeta(total=total, limit=limit, offset=offset)
     )