A detailed migration plan has been added to replace the DevExpress PDF viewer in `EnvelopeSenderEditorPage.razor` with a new WebAssembly (WASM)-based PDF editor component.
The plan outlines the scope, constraints, and implementation strategy, ensuring feature parity, backend compatibility, and minimal disruption to the existing user experience. Key decisions include creating a reusable `SenderPdfImageEditor` component, using server-side PDF rasterization, and removing `esid` and `IMemoryCache`-based session persistence.
The document also defines testing and acceptance criteria to verify the migration's success, focusing on visual fidelity, functionality, and backend contract consistency.
