// Stub — provides useTweaks hook and no-op panel components for preview.
function useTweaks(initial) {
  const [tweaks, setTweaks] = React.useState(initial || {});
  const setTweak = (key, value) => setTweaks(function(prev) {
    return Object.assign({}, prev, { [key]: value });
  });
  return [tweaks, setTweak];
}
function TweaksPanel() { return null; }
function TweakSection() { return null; }
function TweakRadio() { return null; }
function TweakSelect() { return null; }