Removed `@rendermode="InteractiveAuto"` from `<HeadOutlet />` and `<Routes />` in `App.razor` to adjust rendering mode. Updated `EnvelopeReceiverPage_DxPdfViewer.razor` to use `DevExpress.Blazor.PdfViewer` instead of `DevExpress.Blazor`. Added `@using DevExpress.Blazor` to `_Imports.razor` for project-wide access to DevExpress components. Embedded `Resources\Invoice.pdf` in `EnvelopeGenerator.WebUI.csproj` and added the PDF file to the project.
Introduced a new Blazor WebAssembly project (`EnvelopeGenerator.WebUI.Client`) targeting .NET 8.0 for client-side functionality.
Added a Blazor Server project (`EnvelopeGenerator.WebUI`) to host the application and enable server-side rendering.
Created essential Razor components (`MainLayout.razor`, `Home.razor`, `Routes.razor`, `Error.razor`, etc.) for layouts, routing, and error handling.
Configured project files, solution structure, and build settings. Added necessary styles, app settings, and launch profiles for development.
