View card sensitive details

Retrieve encrypted sensitive card details, such as cvv and card_number.

Security Requirements:

1. Generate RSA key pair (2048-bit minimum).
2. Base64-encode the public key modulus (N component).
3. Send encoded public key in X-Client-Public-Key header.
4. Server returns cvv and card_number encrypted with your public key.
5. Decrypt response using your private key.