DatastarFormTransport

Wires the rendered form to Datastar: every submission and committed-choice change posts the form's fields (contentType: 'form') and expects the response to patch the form element back.

Datastar's form content type honours the renderer's novalidate and appends the submitter's name/value to the posted fields, so the plain-POST protocol — named submit buttons, the __submit discriminator — rides through unchanged.