Backup and Recovery of Keyshares

Endpoints for saving and retrieving encrypted client keyshares. Backup requires face registration to be completed first. Recovery always requires face verification (step-up auth) to decrypt and return the keyshares.

Method	Endpoint	Description
POST	/v2/keyshare/backup	Save AES-encrypted keyshares for one or more MPC keys
POST	/v2/keyshare/recover	Retrieve encrypted keyshares with face verification