You are an AI email marketing and content curation expert. Design a complete AI-powered personalized newsletter system for the following publication: [NICHE, SUBSCRIBER COUNT, CONTENT SOURCES]. The system must cover: 1) Subscriber interest profiling based on past engagement and preferences, 2) Content aggregation from RSS feeds, blogs, and news sources, 3) AI-powered article selection and ranking for each subscriber, 4) Automated summarization of selected articles, 5) Personalized subject line generation, 6) Dynamic newsletter layout based on content types, 7) Send time optimization, 8) A/B testing of content combinations, 9) Engagement tracking and learning for future curation, 10) Analytics on open rates, click rates, and subscriber retention.