Update web-ui.md with Edit Sections feature documentation

Author: Bob Strahan

docs/web-ui.md

@@ -26,6 +26,66 @@ The solution includes a responsive web-based user interface built with React tha
 - **Document Process Flow visualization** for detailed workflow execution monitoring and troubleshooting
 - **Document Analytics** for querying and visualizing processed document data
 
+## Edit Sections
+
+The Edit Sections feature provides an intelligent interface for modifying document section classifications and page assignments, with automatic reprocessing optimization for Pattern-2 and Pattern-3 workflows.
+
+### Key Capabilities
+
+- **Section Management**: Create, update, and delete document sections with validation
+- **Classification Updates**: Change section document types with real-time validation
+- **Page Reassignment**: Move pages between sections with overlap detection
+- **Intelligent Reprocessing**: Only modified sections are reprocessed, preserving existing data
+- **Immediate Feedback**: Status updates appear instantly in the UI
+- **Pattern Compatibility**: Available for Pattern-2 and Pattern-3, with informative guidance for Pattern-1
+
+### How to Use
+
+1. Navigate to a completed document's detail page
+2. In the "Document Sections" panel, click the "Edit Sections" button
+3. **For Pattern-2/Pattern-3**: Enter edit mode with inline editing capabilities
+4. **For Pattern-1**: View informative modal explaining BDA architecture differences
+
+#### Editing Workflow (Pattern-2/Pattern-3)
+
+1. **Edit Section Classifications**: Use dropdowns to change document types
+2. **Modify Page Assignments**: Edit comma-separated page IDs (e.g., "1, 2, 3")
+3. **Add New Sections**: Click "Add Section" for new document boundaries  
+4. **Delete Sections**: Use remove buttons to delete unnecessary sections
+5. **Validation**: Real-time validation prevents overlapping pages and invalid configurations
+6. **Submit Changes**: Click "Save & Process Changes" to trigger selective reprocessing
+
+### Processing Optimization
+
+The Edit Sections feature uses **2-phase schema knowledge optimization**:
+
+#### Phase 1: Frontend 
+- **Selective Payload**: Only sends sections that actually changed
+- **Validation Engine**: Prevents invalid configurations before submission
+
+#### Phase 2: Backend   
+- **Pipeline**: Processing functions automatically skip redundant operations
+  - **OCR**: Skips if pages already have OCR data
+  - **Classification**: Skips if pages already classified
+  - **Extraction**: Skips if sections have extraction data
+  - **Assessment**: Skips if extraction results contain assessment data
+- **Selective Reprocessing**: Only modified sections lose their data and get reprocessed
+
+### Pattern Compatibility
+
+#### Pattern-2 and Pattern-3 Support
+- **Full Functionality**: Complete edit capabilities with intelligent reprocessing
+- **Performance Optimization**: Automatic selective processing for efficiency  
+- **Data Preservation**: Unmodified sections retain all processing results
+
+#### Pattern-1 Information
+Pattern-1 uses **Bedrock Data Automation (BDA)** with automatic section management. When Edit Sections is clicked, users see an informative modal explaining:
+
+- **Architecture Differences**: BDA handles section boundaries automatically
+- **Alternative Workflows**: Available options like "View/Edit Data", Configuration updates, and document reprocessing
+- **Future Considerations**: Guidance on using Pattern-2/Pattern-3 for fine-grained section control
+
+
 ## Document Analytics
 
 The Document Analytics feature allows users to query their processed documents using natural language and receive results in various formats including charts, tables, and text responses.