fix: optional fields in embeds (#1691)

Fix optional fields blocking the signature process in embeds

packages/trpc/server/field-router/router.ts

@@ -452,7 +452,7 @@ export const fieldRouter = router({
       return await signFieldWithToken({
         token,
         fieldId,
-        value,
+        value: value ?? '',
         isBase64,
         userId: ctx.user?.id,
         authOptions,

packages/trpc/server/field-router/schema.ts

@@ -153,7 +153,7 @@ export const ZSetFieldsForTemplateResponseSchema = z.object({
 export const ZSignFieldWithTokenMutationSchema = z.object({
   token: z.string(),
   fieldId: z.number(),
-  value: z.string().trim(),
+  value: z.string().trim().optional(),
   isBase64: z.boolean().optional(),
   authOptions: ZRecipientActionAuthSchema.optional(),
 });