Update the CROSS_DEVICE_PROBLEM_ZUSAMMENFASSUNG.md to clarify the role of tunnel servers in the Cross-Device authentication process and outline troubleshooting steps. Additionally, enhance the registrieren.vue component with detailed information about the FIDO Cross-Device flow, including QR-Code format, connection requirements, and potential issues. Improve the register-passkey-options API documentation to reflect the use of tunnel servers, ensuring better understanding and support for Cross-Device functionality.
Add additional debug statements to the register-passkey-options API to validate the options structure, including checks for challenge type and user ID format. Improve logging to capture detailed information about the options being returned, aiding in troubleshooting and ensuring compliance with Cross-Device requirements.