docs: reorganize documentation structure with 7-item folder limits

- Create logical sub-folder classification for all documentation
- Organize 91 migration files into component-specific folders
- Separate user guides, build system, migration, and development docs
- Maintain maximum 7 items per folder for easy navigation
- Add comprehensive README and reorganization summary
- Ensure all changes tracked in git with proper versioning

Structure:
- user-guides/ (3 items): user-facing documentation
- build-system/ (3 items): core, platforms, automation
- migration/ (6 items): assessments, testing, templates
- development/ (4 items): tools and standards
- architecture/, testing/, examples/ (ready for future docs)

Total: 24 folders created, all within 7-item limits

docs/migration/migration-testing/audits/DATAEXPORTSECTION_PRE_MIGRATION_AUDIT.md

@@ -0,0 +1,76 @@
+# DataExportSection.vue Migration Audit
+
+## Component Overview
+- **File**: `src/components/DataExportSection.vue`
+- **Size**: 163 lines (Medium Complexity)
+- **Purpose**: Data export and seed backup functionality with platform-specific behavior
+- **Migration Target**: Enhanced Triple Migration Pattern
+
+## Migration Status: ⏳ READY FOR MIGRATION
+
+### Pre-Migration Analysis
+- **Database Operations**: ✅ Already using PlatformServiceMixin
+- **SQL Queries**: ✅ No raw SQL queries found
+- **Notification Usage**: ✅ Already using modern notification helpers
+- **Template Complexity**: ⏳ Needs Phase 4 (Template Streamlining)
+
+### Migration Requirements
+- ✅ **Phase 1**: Database Migration - NOT NEEDED (already migrated)
+- ✅ **Phase 2**: SQL Abstraction - NOT NEEDED (no raw SQL)
+- ✅ **Phase 3**: Notification Migration - NOT NEEDED (already modern)
+- ⏳ **Phase 4**: Template Streamlining - NEEDED (long CSS classes)
+
+### Component Features to Migrate
+- **Data Export**: Database export to JSON file functionality
+- **Seed Backup**: Router link to seed backup page
+- **Platform Detection**: Platform-specific UI and behavior
+- **Error Handling**: Comprehensive error handling with notifications
+- **Loading States**: Export progress indication
+- **File Management**: Platform-specific file handling
+
+### Technical Analysis
+- **Database Operations**: Uses `this.$contacts()` from PlatformServiceMixin
+- **Notification System**: Uses `createNotifyHelpers` with proper patterns
+- **Platform Service**: Uses `this.platformService.writeAndShareFile()`
+- **Template Classes**: 8+ long CSS classes that can be extracted
+- **Methods**: 2 methods with good documentation
+- **Computed Properties**: 1 computed property (`fileName`)
+
+### Migration Complexity Assessment
+- **Database Migration**: Low (already migrated)
+- **SQL Abstraction**: Low (no raw SQL)
+- **Notification Migration**: Low (already modern)
+- **Template Streamlining**: Medium (8+ long classes to extract)
+- **Overall Complexity**: Low-Medium
+
+### Estimated Migration Time
+- **Conservative Estimate**: 8-12 minutes
+- **Optimistic Estimate**: 4-6 minutes
+- **Based on**: Template streamlining complexity, good existing structure
+
+### Risk Assessment
+- **Risk Level**: Low
+- **Potential Issues**: None identified
+- **Dependencies**: PlatformServiceMixin, notification helpers
+- **Testing Requirements**: Export functionality, platform detection
+
+### Migration Strategy
+1. **Phase 4 Focus**: Extract long CSS classes to computed properties
+2. **Documentation**: Enhance existing documentation
+3. **Template Cleanup**: Improve template readability
+4. **Validation**: Ensure export functionality remains intact
+
+### Success Criteria
+- ✅ All long CSS classes extracted to computed properties
+- ✅ Template complexity reduced
+- ✅ Export functionality preserved
+- ✅ Platform-specific behavior maintained
+- ✅ Error handling preserved
+- ✅ Lint validation passes
+
+### Next Steps
+- ⏳ Begin Phase 4 (Template Streamlining)
+- ⏳ Extract CSS classes to computed properties
+- ⏳ Update documentation
+- ⏳ Validate functionality
+- ⏳ Create migration completion document