Drop detail pages now show metadata in a dedicated card

Drop detail pages now display source, version, domain, publication date, and repository information in a dedicated Metadata card placed between the drop header and the update body. The header is simplified to show the drop title and the “Open original” action, giving the page a clearer hierarchy (title and action first, metadata second, update content third) and matching the metadata card pattern used elsewhere in Hive. The card also adapts with responsive stacking on narrow screens, so the reorganization remains readable on mobile.