Fix migration dates, add multi-platform testing infrastructure, and organize docs

Migration Date Corrections:
- Update all migration TODO comments to use correct date: 2025-07-06
- Add proper TypeScript type declarations for $route and $router in DeepLinkErrorView
- Fix template property references to use $route instead of route

Multi-Platform Testing Infrastructure:
- Add comprehensive multi-platform testing requirements for migrations
- Update component migration template with platform testing requirements
- Establish sign-off requirements for web, desktop, and mobile platforms
- Document expected outcomes and validation procedures

Migration Testing Organization:
- Create docs/migration-testing/ folder for testing documentation
- Move TESTING_CONTACTIMPORT.md from project root to migration-testing/
- Relocate all migration-checklist-*.md files to migration-testing/
- Add comprehensive README.md with organization guidelines
- Update file references in components and TODOs
- Establish naming conventions and quality standards

Files added:
- docs/migration-testing/README.md
- docs/migration-testing/TESTING_CONTACTIMPORT.md
- docs/migration-testing/migration-checklist-ContactImportView.md
- docs/migration-testing/migration-checklist-MembersList.md

Files modified:
- src/views/ContactImportView.vue (date correction)
- src/components/MembersList.vue (date correction, reference path update)
- src/views/DeepLinkErrorView.vue (date correction, Vue router types)
- docs/migration-templates/component-migration.md (multi-platform requirements)

Files moved:
- TESTING_CONTACTIMPORT.md → docs/migration-testing/
- docs/migration-checklist-*.md → docs/migration-testing/

This establishes comprehensive testing infrastructure for all future migrations
with proper organization and multi-platform validation requirements.

docs/migration-testing/README.md

@@ -0,0 +1,112 @@
+# Migration Testing Documentation
+
+This folder contains testing documentation and checklists for PlatformServiceMixin migration validation.
+
+## Folder Structure
+
+```
+docs/migration-testing/
+├── README.md                                  # This file
+├── TESTING_CONTACTIMPORT.md                   # Quick testing guide for ContactImportView
+├── migration-checklist-ContactImportView.md  # Comprehensive testing checklist
+├── migration-checklist-MembersList.md        # Comprehensive testing checklist
+└── [future-migration-checklists.md]          # Additional component checklists
+```
+
+## Document Types
+
+### Quick Testing Guides (`TESTING_*.md`)
+- **Purpose**: Ready-to-use testing instructions for immediate validation
+- **Content**: Test URLs, validation steps, success criteria
+- **Usage**: During active development and testing
+- **Format**: `TESTING_[ComponentName].md`
+
+### Migration Checklists (`migration-checklist-*.md`)
+- **Purpose**: Comprehensive testing documentation for component migrations
+- **Content**: Detailed test cases, platform requirements, sign-off checklists
+- **Usage**: Complete migration validation and documentation
+- **Format**: `migration-checklist-[ComponentName].md`
+
+## Testing Workflow
+
+### 1. Component Migration Completed
+- Create comprehensive migration checklist using template
+- Document all changes and requirements
+- Include platform-specific testing notes
+
+### 2. Quick Testing Setup
+- Create quick testing guide with URLs and validation steps
+- Prepare test data and scenarios
+- Set up development environment
+
+### 3. Platform Testing
+- **Web**: Test in Chrome, Firefox, Safari
+- **Desktop**: Test Electron app on Windows, macOS, Linux
+- **Mobile**: Test Capacitor app on iOS, Android
+
+### 4. Validation and Sign-Off
+- Complete all checklist items
+- Document results and any issues
+- Get sign-off for each platform
+- Mark migration as complete
+
+## Related Documentation
+
+- **Migration Templates**: `../migration-templates/`
+- **Best Practices**: `../migration-templates/best-practices.md`
+- **Component Migration Guide**: `../migration-templates/component-migration.md`
+
+## Usage Examples
+
+### Testing a New Migration
+1. Copy template from `../migration-templates/component-migration.md`
+2. Create `migration-checklist-[Component].md` in this folder
+3. Create `TESTING_[Component].md` for quick validation
+4. Follow testing workflow above
+5. Document results and get platform sign-offs
+
+### Referencing in Component Files
+```typescript
+// Reference: docs/migration-testing/migration-checklist-[Component].md
+```
+
+## File Naming Conventions
+
+- **Quick Testing**: `TESTING_[ComponentName].md`
+- **Migration Checklist**: `migration-checklist-[ComponentName].md`
+- **Use PascalCase** for component names (e.g., `ContactImportView`, `MembersList`)
+- **Keep consistent** with Vue component file names
+
+## Testing Infrastructure
+
+### Required Tools
+- Web browser with developer tools
+- Development server running
+- Database inspection tools (IndexedDB viewer)
+- Platform-specific debugging tools
+
+### Test Data Templates
+Each testing document should include:
+- Valid test data examples
+- Invalid data for error testing
+- Edge case scenarios
+- Performance test cases
+
+## Quality Standards
+
+### All Testing Documents Must Include
+- ✅ Multi-platform testing requirements
+- ✅ Functional test cases
+- ✅ Error handling validation
+- ✅ Database operation verification
+- ✅ Logging validation
+- ✅ Performance criteria
+- ✅ Sign-off checklists
+
+### Migration Completion Criteria
+- ✅ Web platform tested and signed off
+- ✅ Desktop platform tested and signed off
+- ✅ Mobile platform tested and signed off
+- ✅ No regressions identified
+- ✅ Performance meets standards
+- ✅ Documentation complete