Implement address book functionality #396

[Mosas2000]

Summary

This PR implements the address book feature requested in issue #396, allowing users to save and manage frequently used Stacks addresses with custom labels.

Changes

Core Features

• Add/Edit/Delete: Full CRUD operations for address entries
• Search: Real-time filtering by label, address, or notes
• Import/Export: JSON-based backup and restore functionality
• Compact Mode: Streamlined view for quick address selection in SendTip

Components

• AddressBook: Main component with full functionality
• AddressBookEntry: Individual address entry display with actions
• AddressBookForm: Form for adding and editing addresses
• AddressBookSearch: Search input with clear functionality
• AddressBookImportExport: Import/export interface with tabs

Storage & Validation

• addressBook.js: LocalStorage-based persistence layer
• addressValidation.js: Validation utilities for entries
• Duplicate address prevention
• Input sanitization and length enforcement

Testing

• Comprehensive unit tests for storage layer (328 lines)
• Validation tests for all input fields (138 lines)
• Component tests for UI interactions (237 lines)
• All tests passing

Styling

• Full Tailwind CSS integration
• Dark mode support
• Responsive design for mobile and desktop
• Lucide icons for consistent UI

Analytics

• Track add, update, delete operations
• Track import/export usage
• Track search and selection events
• Metrics included in analytics summary

Accessibility

• ARIA labels and roles throughout
• Semantic HTML structure
• Keyboard navigation support
• Screen reader friendly

Documentation

• Comprehensive feature documentation
• Usage instructions
• Technical implementation details
• Troubleshooting guide

Acceptance Criteria

• Address book UI component
• LocalStorage storage
• Add, edit, delete addresses
• Search and filter functionality
• Import/export capability
• Tests for address book

Testing

Run tests with:

npm test addressBook
npm test addressBookValidation
npm test AddressBook

Related Issue

Closes #396