[Accessibility] Checkbox requires two keypresses to toggle with screen reader #3212

Steps to reproduce

1. Open a form containing checkbox questions
2. Navigate to a checkbox field using Tab key
3. Press Space or Enter to check it

Observed behavior
Two keypresses are required to toggle a checkbox.
The first keypress is captured by the screen reader,
the second keypress reaches the component.
This happens with both Space and Enter keys.
Unchecking also requires two keypresses.

Expected behavior
A single keypress should toggle the checkbox,
as with a standard native HTML checkbox.

Relevant standard
This violates WCAG 2.1 success criterion 4.1.2
(Name, Role, Value), which requires that UI components
work correctly with assistive technologies.

Impact
Checkbox questions are effectively unusable for screen
reader and braille display users without manually
switching out of forms mode, which is a significant
accessibility barrier.