"Design a comprehensive IoT-based energy monitoring system for residential use, focusing on real-time energy usage monitoring, automated alerts for unusual consumption patterns, and integration with smart home devices. Provide a detailed, step-by-step guide for intermediate-level developers,** including:** ## 1. System architecture and component selection (hardware and software). ## 2. Real-time energy usage monitoring implementation. ## 3. Automated alert system for unusual consumption patterns. ## 4. Integration with smart home devices. ## 5. Potential challenges and proposed solutions. Include relevant technical specifications, diagrams, and examples to support each step. Ensure the system design is scalable, secure, and user-friendly."