Render hint — whether to display as a checkbox or a switch toggle.
Validation error message shown when required is true and value is false.
OptionalrichContent?: RichContentOptional rich content with template text and named link replacements.
Current checked state (mutable — set via next()).
Corresponds to the native BOOLEAN inputType / SINGLE_CHECKBOX server type.
Extends BaseCollector — has key, label, and required.
When required is true and value is false, the native SDK's validate()
emits a validation error using errorMessage. JS consumers should surface
errorMessage to the user in that case.
Single checkbox or toggle collector.