feat: #3594479 Expose render_validation_on_save toggle to client-side JSON Editor
Exposes the render_validation_on_save toggle to the client-side JSON Editor
so editors with invalid stored content can save through the browser UI when
enforcement is disabled. Closes the gap left by [#3589846], which added the
server-side toggle but could not reach the independently-operating JSON Editor.
Closes #3594479