Workflow "checkbox" additional note field always evaluates to false under Studio API (strict `=== 'true'` vs. hydrated boolean)

[Kovaloff]

Affected Version

2026.1

Affected capability

Core

Steps to reproduce

Define a transition with a required checkbox additional field:
```yaml
transitions:
request_product_approval:
from: 'in_development'
to: 'in_approval'
options:
notes:
additionalFields:
-
name: 'marketingInvolved'
title: 'Please confirm that Marketing was sufficiently involved'
required: true
fieldType: checkbox

Actual Behavior

A workflow transition additionalFields entry with fieldType: checkbox is always read as false, regardless of whether the user checks it. When the field is required: true, the transition can never be submitted - it always fails with the "field is required" validation error.

Root cause

Pimcore\Workflow\EventSubscriber\NotesSubscriber::getAdditionalDataForField()
(lib/Workflow/EventSubscriber/NotesSubscriber.php:212-213):

if ($fieldConfig['fieldType'] === 'checkbox') {
    return $data === 'true';
}

Expected Behavior

Checking the box satisfies the required field and the transition is applied.