Product pages default; mobile app releases now compact

Added

• Product pages are now the default landing and feed unit: a bare /org/product URL resolves to the product hub, complete with its own activity timeline, heatmap, and per-product Atom feed.
• Search results and MCP search hits now show the owning product for each release.
• Owners and curators can rename an organization, product, or source display name directly from the admin menus.

Changed

• Mobile app releases now render as a compact app-update row instead of the standard version-and-screenshot layout.