[BUG] AsyncEventQueue error state lost after first read

[Livezt]

Bug: AsyncEventQueue Error State Loss

File: src/web/client/GatewayBrowserClient.ts lines 327-332

private next(): Promise<IteratorResult<T>> {
  if (this.error) {
    const err = this.error;
    this.error = undefined;  // Error cleared after first read!

Impact: After error is consumed once, subsequent calls return {done: true} instead of the error. Retries get wrong state.

Recommended Fix: Store error persistently or use a queue that preserves error state.