Updated the `_dotNetRef` field to use a more specific type, `DotNetObjectReference<EnvelopeReceiverPage_DxReportViewer>`, for better alignment with the component. Removed obsolete redirection logic from `/receiver/{key}` to `/envelope/{key}` in `OnInitializedAsync`, as it is no longer needed or handled elsewhere. Retained envelope access validation logic.
Introduced a new Razor page `EnvelopeReceiverPage_DxReportViewer.razor` to manage and sign envelope-related documents. Integrated DevExpress Blazor components for PDF rendering and signature handling.
Key features:
- Added sections for envelope info, signature actions, and a PDF viewer.
- Enabled signature creation via drawing, text input, or image upload.
- Validated and applied signatures to annotated fields in the document.
- Integrated JavaScript interop for signature capture and rendering.
- Supported exporting signed PDFs and dynamic signature overlays.
- Ensured proper resource cleanup with `IDisposable` implementation.
