feat: Add comprehensive security, monitoring, and advanced examples to iframe-integration-suite

[Copilot]

This PR significantly enhances the iframe-integration-suite with enterprise-grade security features, performance monitoring capabilities, and production-ready examples. The changes transform this from a basic toolkit into a comprehensive, security-first iframe integration solution.

🔒 New Security Features

Added a complete SecurityUtils module providing:

import { SecurityUtils } from 'iframe-integration-suite/utils';

// Origin validation with pattern matching
const isValid = SecurityUtils.validateOrigin('https://api.example.com', ['*.example.com']);

// HTML sanitization with XSS protection
const cleanHtml = SecurityUtils.sanitizeHtml(userContent, {
  allowedTags: ['p', 'div', 'a'],
  stripDangerous: true
});

// CSP generation for iframe security
const csp = SecurityUtils.generateCSP({
  allowedSources: ["'self'", 'https://trusted-api.com']
});

Enhanced RPC communication with built-in security validation, rate limiting, and secure message ID generation.

📊 Performance Monitoring

New MonitoringUtils module enables comprehensive iframe health monitoring:

import { MonitoringUtils } from 'iframe-integration-suite/utils';

// Real-time health monitoring with automatic recovery
const monitor = MonitoringUtils.createHealthMonitor(iframe, {
  onHealthChange: (isHealthy) => {
    console.log(`Frame health: ${isHealthy ? 'healthy' : 'needs attention'}`);
  }
});

// Performance tracking with detailed metrics
const tracker = MonitoringUtils.createPerformanceTracker();
const { result, duration } = await tracker.measureAsync('rpc-call', () => rpc.call('getData'));

🎯 Production-Ready Examples

Authentication Flow Example

Complete OAuth and form-based authentication implementation with:

• Secure token handling and session management
• Real-time authentication status updates
• Comprehensive error handling with user feedback
• Health monitoring integration

File Upload Example

Advanced file upload system featuring:

• Drag & drop interface with visual feedback
• Real-time progress tracking and validation
• Security-first file processing with type/size validation
• Queue management for multiple file uploads

🔧 Enhanced Core Modules

FrameManager now includes:

• Integrated health monitoring and security features
• Comprehensive frame statistics and error tracking
• Secure frame creation with CSP and sandbox options

const manager = new FrameManager({
  allowedOrigins: ['https://trusted-domain.com'],
  enableHealthMonitoring: true,
  enableSecurity: true
});

// Create secure iframe with restrictive permissions
const iframe = manager.createSecureFrame(url, {
  sandbox: ['allow-scripts', 'allow-forms'],
  enableCSP: true
});

RPC System enhanced with:

• Origin validation and rate limiting
• Performance metrics and response time tracking
• Secure message validation and error handling

🚀 Modern JavaScript Support

• Full ES module migration (type: "module")
• Updated all modules for modern JavaScript (ES2020+)
• Comprehensive JSDoc documentation
• Zero external dependencies for core functionality

🧪 CI/CD Integration

Added GitHub Actions workflow with:

• Multi-version testing (Node.js 18.x, 20.x)
• Cross-browser testing (Chrome, Firefox, Safari)
• Security auditing and vulnerability scanning
• Automated deployment pipeline

📚 Enhanced Documentation

Completely rewritten README with:

• Comprehensive API documentation
• Security best practices guide
• Performance optimization recommendations
• Migration guide for existing users
• Troubleshooting and debugging sections

🔄 Breaking Changes

• Package now requires ES module support (type: "module")
• Constructor options updated for enhanced security configuration
• Some imports may need to be updated for new module structure

Migration Example

// Before
const manager = new FrameManager();

// After  
const manager = new FrameManager({
  allowedOrigins: ['*'],  // Explicit configuration required
  enableSecurity: true    // Security enabled by default
});

This update transforms iframe-integration-suite into an enterprise-ready toolkit with comprehensive security, monitoring, and real-world examples suitable for production applications.

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