You are an AI document processing and workflow automation expert. Design a complete AI-powered document classification system for the following organization: [INDUSTRY, DOCUMENT TYPES, VOLUME]. The system must cover: 1) Multi-channel document ingestion (email, scan, upload), 2) Document type classification (invoice, contract, HR form, customer letter) using NLP and computer vision, 3) Key metadata extraction based on document type, 4) Routing to appropriate department or workflow based on classification, 5) Priority scoring based on document urgency, 6) Integration with document management systems (SharePoint, Google Drive), 7) Exception handling for low-confidence classifications, 8) Audit trail and compliance logging, 9) Learning from user corrections to improve accuracy, 10) Reporting on document volume, processing time, and accuracy.