fix: checkbox logic (#1537)

## Description

<!--- Describe the changes introduced by this pull request. -->
<!--- Explain what problem it solves or what feature/fix it adds. -->

## Related Issue

<!--- If this pull request is related to a specific issue, reference it
here using #issue_number. -->
<!--- For example, "Fixes #123" or "Addresses #456". -->

## Changes Made

<!--- Provide a summary of the changes made in this pull request. -->
<!--- Include any relevant technical details or architecture changes.
-->

- Change 1
- Change 2
- ...

## Testing Performed

<!--- Describe the testing that you have performed to validate these
changes. -->
<!--- Include information about test cases, testing environments, and
results. -->

- Tested feature X in scenario Y.
- Ran unit tests for component Z.
- Tested on browsers A, B, and C.
- ...

## Checklist

<!--- Please check the boxes that apply to this pull request. -->
<!--- You can add or remove items as needed. -->

- [ ] I have tested these changes locally and they work as expected.
- [ ] I have added/updated tests that prove the effectiveness of these
changes.
- [ ] I have updated the documentation to reflect these changes, if
applicable.
- [ ] I have followed the project's coding style guidelines.
- [ ] I have addressed the code review feedback from the previous
submission, if applicable.

## Additional Notes

<!--- Provide any additional context or notes for the reviewers. -->
<!--- This might include details about design decisions, potential
concerns, or anything else relevant. -->

packages/lib/server-only/field/sign-field-with-token.ts

@@ -8,6 +8,7 @@ import { validateDropdownField } from '@documenso/lib/advanced-fields-validation
 import { validateNumberField } from '@documenso/lib/advanced-fields-validation/validate-number';
 import { validateRadioField } from '@documenso/lib/advanced-fields-validation/validate-radio';
 import { validateTextField } from '@documenso/lib/advanced-fields-validation/validate-text';
+import { fromCheckboxValue } from '@documenso/lib/universal/field-checkbox';
 import { prisma } from '@documenso/prisma';
 import { DocumentStatus, FieldType, SigningStatus } from '@documenso/prisma/client';
 
@@ -119,7 +120,8 @@ export const signFieldWithToken = async ({
 
   if (field.type === FieldType.CHECKBOX && field.fieldMeta) {
     const checkboxFieldParsedMeta = ZCheckboxFieldMeta.parse(field.fieldMeta);
-    const checkboxFieldValues = value.split(',');
+    const checkboxFieldValues: string[] = fromCheckboxValue(value);
+
     const errors = validateCheckboxField(checkboxFieldValues, checkboxFieldParsedMeta, true);
 
     if (errors.length > 0) {