Without .ThenInclude(i => i.Item), the OwnedItemEntry.Item nav defaults to a
new ItemEntry() with Id=0 (project_ef_nav_include_pitfall), so the
FirstOrDefault(i => i.Item.Id == ticketItemId) lookup never matched. The
ticket was never decremented and reward_list omitted the post-state entry —
on the next /tutorial/pack_info the pack stayed visible and the client
re-clicked into plain /pack/open, which 501s on type_detail=5.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>