🚨 BREAKING CHANGES: - Removed AccountOperationVisitor & legacy IQueenBee interface - New chain-observers architecture - QueenBee API redesigned with fluent pattern - EventEmitter → observable pattern - Node.js 20+ required ✨ NEW FEATURES: - Chain-observers system (130+ file changes) - Past data provider for historical analysis 🐛 BUG FIXES: - Transaction broadcasting improvements - Better error handling - Memory optimizations 📚 MIGRATION NEEDED: - accountOperations() → chain-observers pattern - Direct QueenBee methods → fluent API 📈 Stats: 130 commits, 13k+ lines added