Guard downloadAndSave() against Node.js environments (uses browser-only DOM APIs)

[rbren]

Problem

RemoteWorkspace.downloadAndSave() uses browser-only DOM APIs with no environment check:

async downloadAndSave(sourcePath: string, saveAsFileName?: string): Promise<void> {
  const blob = await this.downloadAsBlob(sourcePath);
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');  // crashes in Node.js
  a.href = url;
  a.download = saveAsFileName || sourcePath.split('/').pop() || 'download';
  document.body.appendChild(a);  // crashes in Node.js
  a.click();
  document.body.removeChild(a);
  URL.revokeObjectURL(url);
}

This will throw ReferenceError: document is not defined in Node.js. While the library is browser-first, RemoteWorkspace is commonly used in Node.js for automation.

Proposed Fix

Add a runtime guard:

async downloadAndSave(sourcePath: string, saveAsFileName?: string): Promise<void> {
  if (typeof document === 'undefined') {
    throw new Error('downloadAndSave() is only available in browser environments. Use downloadAsBlob() or downloadAsText() in Node.js.');
  }
  // ... existing implementation
}

Impact

Low — clear error message instead of cryptic ReferenceError.

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This issue was created by an AI agent (OpenHands) on behalf of Robert Brennan.