The `PsPdfKitAnnotation` property in the `SignCommand` class has been marked as `[Obsolete]` with a deprecation message suggesting the use of `Signature.Commands.SignCommand` instead.
The `TemplateType` property, which returned the `EmailTemplateType.DocumentSigned` value, has been removed from the `SignCommand` class.
Updated namespaces from `Signature` to `Signatures` for consistency and clarity across the application. Simplified pipeline behavior registrations in `DependencyInjection.cs` by using shorter references. Added `Microsoft.Extensions.Configuration` to `DependencyInjection.cs` to support configuration functionality. Ensured all references to `SignCommand` and related behaviors align with the new namespace structure.
