iOS and macOS apps tracked; MCP release-feed improved

Added

• Track iOS and macOS apps: App Store versions are now indexed as releases, with app icons, platform badges, and an "Available on" affordance on product and source pages.
• MCP release-feed tools now drill from a list into release detail with full, web-parity markdown and inline images.

Changed

• Long overview source lists now collapse behind a "Show more" toggle and release thumbnails are downscaled for a tidier layout.