Function normalizedUpperBound

src/utils/exportRenderer.tsx:37–41

(m: Message)

// NormalizedMessages — 1:1 with block count. String content = 1 block.
// AttachmentMessage etc. have no .message and normalize to ≤1.
function normalizedUpperBound(m: Message): number {
  if (!('message' in m)) return 1;
  const c = m.message.content;
  return Array.isArray(c) ? c.length : 1;
}

/**
 * Streams rendered messages in chunks, ANSI codes preserved. Each chunk is a