/**
 * Streaming typewriter effect - appends characters to a ref element
 * @param {string} text - Text to stream
 * @param {function} onChar - Called with accumulated text on each character
 * @param {number} delayMs - Delay between characters
 * @param {AbortSignal} signal - Optional abort signal
 */
export async function streamText(text, onChar, delayMs = 8, signal = null) {
  let accumulated = '';
  for (const char of text) {
    if (signal && signal.aborted) break;
    accumulated += char;
    onChar(accumulated);
    await new Promise((r) => setTimeout(r, delayMs));
  }
  return accumulated;
}