Added DevExpress.Reporting.Core package reference. Refactored rptEnvelopeHistory to inherit from XtraReport and build its layout programmatically using DevExpress bands, tables, and styling. The report now uses A4 paper size, custom margins, and DevExpress UI components for rendering.
Introduce four custom exceptions (BurnAnnotationException, CreateReportException, ExportDocumentException, MergeDocumentException) under EnvelopeGenerator.ServiceHost.Exceptions for improved error handling. Update the project file to include the new Extensions folder.
Created a new EnvelopeGenerator.ServiceHost project targeting .NET 8.0. Set up minimal API host with controllers, Swagger/OpenAPI support, and development configuration files. Updated solution to include the new project with appropriate build settings.
