Function removeMarkedSection

src/installer/targets/shared.ts:205–233

(
  filePath: string,
  startMarker: string,
  endMarker: string,
)

 * the markers weren't present, `kept` when the file didn't exist.
 */
export function removeMarkedSection(
  filePath: string,
  startMarker: string,
  endMarker: string,
): 'removed' | 'not-found' | 'kept' {
  if (!fs.existsSync(filePath)) return 'kept';

  let content: string;
  try {
    content = fs.readFileSync(filePath, 'utf-8');
  } catch {
    return 'kept';
  }

  const startIdx = content.indexOf(startMarker);
  const endIdx = content.indexOf(endMarker);
  if (startIdx === -1 || endIdx <= startIdx) return 'not-found';

  const before = content.substring(0, startIdx).trimEnd();
  const after = content.substring(endIdx + endMarker.length).trimStart();
  const joined = before + (before && after ? '\n\n' : '') + after;

  if (joined.trim() === '') {
    try { fs.unlinkSync(filePath); } catch { /* ignore */ }
  } else {
    atomicWriteFileSync(filePath, joined.trim() + '\n');
  }
  return 'removed';
}