Cascade download lifecycle

const signature = await signer.signArbitrary(chainId, address, actionId);

POST /api/v1/actions/cascade/{action_id}/downloads
Content-Type: application/json

{
  "signature": "base64-encoded ADR-036 signature"
}

GET /api/v1/downloads/cascade/{task_id}/status

data: {"status": "processing", "progress": 45}
data: {"status": "processing", "progress": 80}
data: {"status": "completed", "progress": 100}

GET /api/v1/downloads/cascade/{task_id}/file
Content-Type: application/octet-stream

const stream = await client.Cascade.downloader.download(actionId);

// Read the stream
const reader = stream.getReader();
const chunks: Uint8Array[] = [];

while (true) {
  const { done, value } = await reader.read();
  if (done) break;
  chunks.push(value);
}

// Reassemble into a single buffer
const totalLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);
const result = new Uint8Array(totalLength);
let offset = 0;
for (const chunk of chunks) {
  result.set(chunk, offset);
  offset += chunk.length;
}

// Decode as text (if applicable)
const text = new TextDecoder().decode(result);