Redesigned `EnvelopeSenderPage.razor` to include a structured
dashboard layout with a sender action bar and dynamic content
area. Added authorization enforcement with the `@attribute`
directive and dependency injection for services like
`EnvelopeService` and `AuthService`.
Introduced a tabbed interface for managing "Active" and
"Completed" envelopes, with a `DxGrid` component for displaying
envelope details. Added support for filtering, searching, and
row selection, along with detailed row templates for receiver
information.
Implemented methods for loading, refreshing, creating, editing,
and deleting envelopes, as well as logging out. Enhanced error
handling and state management, and added console logging for
debugging. Integrated external stylesheets for improved UI.