Cognitoauth structure

File	Description
`auth.go`	Main package file with exported functions
`handler.go`	HTTP handlers for login, callback, etc.
`middleware.go`	Echo middleware implementation
`jwks.go`	JWKS handling and validation
`token.go`	Token verification and management
`models.go`	Data models and types
`utils.go`	Helper functions
`config.go`	Configuration structures