Method constructor

packages/dataflows/src/errors.ts:15–22

(
    public vendor: string,
    public symbol: string,
    detail?: string,
  )

/** No usable rows (empty result OR stale data). */
export class NoMarketDataError extends VendorError {
  constructor(
    public vendor: string,
    public symbol: string,
    detail?: string,
  ) {
    super(`[${vendor}] no market data for ${symbol}${detail ? `: ${detail}` : ""}`);
    this.name = "NoMarketDataError";
  }
}

/** Rate limited — router skips to the next vendor in the chain. */