Forage detail page splits metadata and body into separate cards

Forage item detail pages now display the item metadata (source, requester, updated date, domain badges) in a separate card above the rendered item body, which sits in its own Details card below. This split applies to manual forage items, GitHub issues, and Grafana alerts, and makes long Markdown-heavy issue bodies easier to scan. The edit form remains in the top card labeled “Edit item”, so the body card is hidden while editing.