Create a WordPress block that displays a curated list of blogs with their latest posts pulled automatically via RSS feeds. In the editor, users add RSS feed URLs through a clean interface with options to set display format (list, grid, or compact), number of entries, and styling preferences. The block validates feeds on input and shows a preview of how the blogroll will appear. On the frontend, the block displays each blog's name, favicon, latest post title, publication date, and optional excerpt in the chosen layout. Posts automatically refresh every few hours via WordPress cron. Include hover effects on entries, with blog names linking to homepages and post titles linking to articles. Support responsive design with mobile-friendly layouts. Add settings for post age limits, excerpt length, and date format. Handle broken feeds gracefully by showing cached content with error indicators. Provide preset styles including classic sidebar list, modern card grid, and minimal text-only layouts. Include OPML import/export functionality for easy blogroll management.