// Runtime worker errors can be logged without rejecting loadModel(). Bound that
// wait and terminate the worker on cancellation, timeout, or a reported failure.
export function startRuntime(start,{signal,stop,timeoutMs=120000,onFailure=()=>{}}){
 return new Promise((resolve,reject)=>{
  let settled=false,started=false,timer;
  const cleanup=()=>{clearTimeout(timer);signal?.removeEventListener('abort',abort);onFailure(null);};
  const fail=error=>{if(settled)return;settled=true;cleanup();Promise.resolve().then(stop).catch(()=>{});reject(error);};
  const abort=()=>fail(signal.reason||new DOMException('Loading canceled','AbortError'));
  onFailure(fail);
  if(signal?.aborted){abort();return;}
  signal?.addEventListener('abort',abort,{once:true});
  timer=setTimeout(()=>fail(new Error('GPU setup did not finish within two minutes. Your downloaded weights are still available in this tab; retry setup or choose a smaller context.')),timeoutMs);
  Promise.resolve().then(()=>{if(settled)return;started=true;return start();}).then(value=>{if(settled){if(started)Promise.resolve().then(stop).catch(()=>{});return;}settled=true;cleanup();resolve(value);},fail);
 });
}