Function assertJsOriginAllowed

browse/src/read-commands.ts:185–209

* When cookies have been imported for specific domains, block JS execution * on pages whose origin doesn't match any imported cookie domain. * Prevents cross-origin cookie exfiltration via `js document.cookie` or * similar when the agent navigates to an untrusted page.

(bm: BrowserManager, pageUrl: string)

 * similar when the agent navigates to an untrusted page.
 */
function assertJsOriginAllowed(bm: BrowserManager, pageUrl: string): void {
  if (!bm.hasCookieImports()) return;

  let hostname: string;
  try {
    hostname = new URL(pageUrl).hostname;
  } catch {
    return; // about:blank, data: URIs — allow (no cookies at risk)
  }

  const importedDomains = bm.getCookieImportedDomains();
  const allowed = [...importedDomains].some(domain => {
    // Exact match or subdomain match (e.g., ".github.com" matches "api.github.com")
    const normalized = domain.startsWith('.') ? domain : '.' + domain;
    return hostname === domain.replace(/^\./, '') || hostname.endsWith(normalized);
  });

  if (!allowed) {
    throw new Error(
      `JS execution blocked: current page (${hostname}) does not match any cookie-imported domain. ` +
      `Imported cookies for: ${[...importedDomains].join(', ')}. ` +
      `This prevents cross-origin cookie exfiltration. Navigate to an imported domain or run without imported cookies.`
    );
  }
}

export async function handleReadCommand(
  command: string,