Refactored `DocumentReceivedNotification` to use new properties `Origin`, `EnvelopeUuid`, and `ReceiverSignature` for constructing `EnvelopeURL`. Updated `LinkToDocument` and `LinkToDocumentText` to derive from `EnvelopeURL`.
Simplified `CreateEnvelopeCommandHandler` with record-like syntax, removing private fields and directly injecting dependencies.
Renamed and refactored `QueueInvitationEmailsAsync` to `SendInvitationEmailsAsync`, using `EnvNtfService.Notify` for email notifications, centralizing logic and improving clarity.
Improved error handling in email sending with logging. Updated variable names for clarity and cleaned up `using` directives.