export function applyUploadedStill(form, response, target) {
  const still=response?.still
  if (!still?.id) throw new Error('The upload did not return a saved still. Please try again.')
  const next={...form,settings:{...form.settings}}
  if (target==='hero') next.identityStillId=still.id
  else {next.imageAId=still.id;if(next.mode!=='extend'){next.startClipId='';next.settings.aspect='auto'}}
  return next
}