Function ensureBrowser

packages/cli/src/browser/manager.ts:354–374

(options?: EnsureBrowserOptions)

 * Resolution: env var -> cached download -> system Chrome -> auto-download.
 */
export async function ensureBrowser(options?: EnsureBrowserOptions): Promise<BrowserResult> {
  const fromEnv = findFromEnv();
  if (fromEnv) return fromEnv;

  const fromCache = await findFromCache();
  if (fromCache.result) return fromCache.result;
  if (fromCache.staleHyperframesCachePath) {
    console.warn(
      `[browser] Cached binary missing at ${fromCache.staleHyperframesCachePath} — re-downloading...`,
    );
    return downloadBrowser(options);
  }

  const fromSystem = findFromSystem();
  if (fromSystem) {
    warnSystemFallbackOnce(fromSystem.executablePath);
    return fromSystem;
  }

  return downloadBrowser(options);
}

async function downloadBrowser(options?: EnsureBrowserOptions): Promise<BrowserResult> {
  if (isLinuxArm()) {