All references to IEnvelopeMailService have been removed from ReceiverAuthController. The controller no longer sends access code emails; this responsibility is now handled by the Web project when generating the link. Updated comments clarify the new flow, and related redundant code has been cleaned up. Authentication and TFA logic remain unchanged.
Introduces ReceiverAuthController with REST endpoints for envelope receiver authentication, replacing the previous web-based flow with a JSON API suitable for Blazor clients. Implements endpoints for status checking, access code validation, and TFA (SMS or authenticator) verification. Adds unified ReceiverAuthResponse and request models for consistent API responses. Includes detailed documentation and error handling, providing a modern, client-friendly authentication flow.
