Describe the problem that you experienced

The stateful-input has multiple errors.
value.set(($event.target as HTMLInputElement).value) throws an error about a missing closing parentheses at column 26
disabledReasons = input<readonly DisabledReason[]>([]); throws an error: Property 'disabledReasons' in type 'StatefulInput' is not assignable to the same property in base type 'FormValueControl'.
errors = input<readonly ValidationError.WithField[]>([]); throws an error: Property 'errors' in type 'StatefulInput' is not assignable to the same property in base type 'FormValueControl'.

I attempted to fix the issues by doing the following:
using (input)="update($event)" and creating update($event:any) { this.value.set(($event.target as HTMLInputElement).value) }
changing the disabledReasons type to disabledReasons = input<readonly WithOptionalField<DisabledReason>[]>([]);
changing the errors type to errors = input<readonly WithOptionalField<ValidationError>[]>([]);
and importing the WithOptionalField type from @angular/forms/signals

Enter the URL of the topic with the problem

https://angular.dev/guide/forms/signals/custom-controls#adding-state-signals

Describe what you were looking for in the documentation

A working example of a custom component with the developer preview version of Signal Forms

Describe the actions that led you to experience the problem

Copying and using the stateful-input component in the documentation

Describe what you want to experience that would fix the problem

A successful build

Add a screenshot if that helps illustrate the problem

No response

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