runBoundedWorkerPool

// Runs zero-argument async task functions with a fixed concurrency limit.
export async function runBoundedWorkerPool(tasks, { concurrency = 4 } = {}) {
  if (!Number.isInteger(concurrency) || concurrency < 1) {
    throw new RangeError('concurrency must be a positive integer');
  }
  const queue = Array.from(tasks);
  const results = new Array(queue.length);
  let cursor = 0;

  async function worker() {
    while (cursor < queue.length) {
      const index = cursor++;
      try {
        results[index] = { status: 'fulfilled', value: await queue[index]() };
      } catch (error) {
        results[index] = { status: 'rejected', reason: error };
      }
    }
  }

  const workers = Array.from({ length: Math.min(concurrency, queue.length) }, worker);
  await Promise.all(workers);
  return results;
}