Switch to a designer-generated DevExpress XtraReport for envelope history, replacing the previous manual layout. Added designer (.Designer.cs), resource (.resx), and updated code-behind (.cs) files. Updated the project file to include new report assets. Changed report generation to use the new async API. This modernizes the report, improves maintainability, and enhances appearance.
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.
