Proper Express.js adapter API for auth lib

[SOG-web]

Description

Create a comprehensive Express.js adapter API for the auth library.

Tasks

• Create Express.js specific middleware
• Implement Express.js route handlers for auth endpoints
• Add Express.js specific error handling
• Create Express.js specific session management
• Implement Express.js specific guards/middleware for protected routes
• Add configuration options for Express.js integration
• Create examples for common Express.js use cases
• Document Express.js adapter usage

Acceptance Criteria

• Express.js adapter works seamlessly with the auth library
• API is intuitive and follows Express.js conventions
• Examples cover common use cases
• Documentation is comprehensive