Get agent

curl --request GET \
  --url https://api.zavu.dev/v1/senders/{senderId}/agent \
  --header 'Authorization: Bearer <token>'

{
  "agent": {
    "id": "agent_abc123",
    "senderId": "sender_12345",
    "name": "Customer Support Agent",
    "enabled": true,
    "provider": "openai",
    "model": "gpt-4o-mini",
    "systemPrompt": "<string>",
    "createdAt": "2023-11-07T05:31:56Z",
    "updatedAt": "2023-11-07T05:31:56Z",
    "contextWindowMessages": 10,
    "includeContactMetadata": true,
    "maxTokens": 123,
    "temperature": 123,
    "triggerOnChannels": [
      "sms",
      "whatsapp"
    ],
    "triggerOnMessageTypes": [
      "text"
    ],
    "stats": {
      "totalInvocations": 123,
      "totalTokensUsed": 123,
      "totalCost": 123
    }
  }
}