Prevent link previews from trimming Open Graph cards

Generated Open Graph cards are now rendered at 1920 by 1008 (instead of 1920 by 1080), with tightened vertical spacing across the brand, title, description, author, and footer areas. This keeps the full card content visible when link previews crop large images to a wider card ratio, so footer metadata is no longer at risk of being trimmed. Previously stored card images also regenerate automatically, thanks to a card renderer version bump that gives them new object keys on the next request.