Function sanitize_authorizer_field_name 

pub fn sanitize_authorizer_field_name(field: &str) -> String

Sanitize authorizer field name for use in HTTP headers

Converts field names to valid HTTP header format:

1. Convert camelCase to snake_case (userId → user_id)
2. ASCII lowercase
3. Replace non-alphanumeric (except _ and -) with dash

Examples

assert_eq!(sanitize_authorizer_field_name("userId"), "user_id");
assert_eq!(sanitize_authorizer_field_name("deviceId"), "device_id");
assert_eq!(sanitize_authorizer_field_name("device_id"), "device_id");
assert_eq!(sanitize_authorizer_field_name("user@email"), "user-email");