OPML/RSS aggregator for IndieWeb blogroll management: - Multiple source types: OPML URL, OPML file, manual entry - Background sync scheduler with configurable intervals - 7-day item retention for fresh content discovery - MongoDB storage for sources, blogs, items - Admin UI for sources and blogs management - Public JSON API endpoints for frontend consumption - OPML export by category Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>