feat: Add React Native Web Support for Auth0 with Class-Based Implementation

[subhankarmaiti]

🎯 Overview

This PR adds full React Native Web (RN Web) support to the react-native-auth0 library by implementing web-specific versions of all core Auth0 classes using the @auth0/auth0-spa-js library.

🚀 What's New

📦 New Web Implementation Files

• src/auth0/index.web.ts - Main Auth0 client with automatic redirect handling
• src/auth/index.web.ts - Auth class with secure SPA-focused methods
• src/webauth/index.web.ts - WebAuth class supporting redirect-based flows
• src/credentials-manager/index.web.ts - Credentials manager using auth0-spa-js token management
• src/management/users.web.ts - Management API client for user operations
• src/specs/NativeA0Auth0.web.ts - Web-compatible native module spec

🔧 Key Features

• 🔐 Secure Authentication Flow: Redirect-based login using Auth0 Universal Login
• 🏗️ Class-Based Architecture: Maintains API compatibility with existing React Native implementation
• ⚡ Automatic Token Management: Leverages auth0-spa-js for secure token storage and refresh
• 🛡️ Security-First Approach: Non-recommended methods throw helpful errors guiding developers to secure flows
• 🔄 Seamless Integration: Drop-in replacement that works with existing Auth0 configurations

🛠️ Implementation Highlights

• Uses @auth0/auth0-spa-js v2.2.0 as the underlying web client
• Automatic redirect callback handling on app initialization
• Memory-based token storage for enhanced security
• Compatible method signatures with mobile implementations
• Comprehensive error handling and developer guidance

📋 Updated Dependencies

• Added @auth0/auth0-spa-js: ^2.2.0 as peer dependency to support web authentication flows

🎯 Benefits

• Cross-Platform Consistency: Same Auth0 API across React Native mobile and web
• Enhanced Developer Experience: No need to learn different APIs for different platforms
• Production Ready: Built with security best practices for SPA applications
• Future Proof: Extensible architecture supporting additional Auth0 features

🧪 Testing

• Compatible with existing React Native Auth0 configurations

[subhankarmaiti]

closing this as we have created a single PR for refactoring