fix: add defaultValue to SignaturePad to persist signatures (#522)

* fix: add defaultValue to SignaturePad to persist signatures

apps/marketing/src/components/(marketing)/widget.tsx

@@ -391,6 +391,7 @@ export const Widget = ({ className, children, ...props }: WidgetProps) => {
 
           <SignaturePad
             className="aspect-video w-full rounded-md border"
+            defaultValue={signatureDataUrl || ''}
             onChange={setDraftSignatureDataUrl}
           />