채팅 메시지 전송

{
  "chat_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "chat_status": "active",
  "input_message_id": 123,
  "output": [
    {
      "id": 123,
      "role": "agent",
      "content": "<string>",
      "created_at": 123,
      "attachments": [
        {
          "file_key": "<string>",
          "mime_type": "<string>"
        }
      ],
      "author": "ai",
      "client_idempotency_key": "<string>"
    }
  ]
}

{
  "chat_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "chat_status": "active",
  "responder": "operator",
  "input_message_id": 123
}

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Request validation failed.",
    "details": {
      "field": "name",
      "reason": "must not be blank"
    }
  }
}

{
  "error": {
    "code": "UNAUTHORIZED",
    "message": "Authentication is required.",
    "details": {}
  }
}

{
  "error": {
    "code": "FORBIDDEN",
    "message": "Permission denied.",
    "details": {}
  }
}

{
  "error": {
    "code": "CHAT_NOT_FOUND",
    "message": "채팅을 찾을 수 없습니다.",
    "details": {
      "chat_id": "22222222-2222-4222-8222-222222222222"
    }
  }
}

{
  "error": {
    "code": "CONFLICT",
    "message": "The requested operation conflicts with current state.",
    "details": {
      "current_status": "draft"
    }
  }
}

{
  "error": {
    "code": "PAYLOAD_TOO_LARGE",
    "message": "요청 본문이 허용 크기를 초과했습니다.",
    "details": {
      "content_length": 11534336,
      "max_bytes": 10485760
    }
  }
}

{
  "error": {
    "code": "CONVERTED_FILE_TOO_LARGE",
    "message": "Converted image size exceeds the 1 MB limit.",
    "details": {
      "converted_size_bytes": 1258291,
      "max_bytes": 1048576
    }
  }
}

{
  "error": {
    "code": "RATE_LIMIT_EXCEEDED",
    "message": "Too many requests.",
    "details": {
      "limit": 10,
      "window_seconds": 1,
      "scope": "user"
    }
  }
}

{
  "error": {
    "code": "INTERNAL_ERROR",
    "message": "Internal server error.",
    "details": {}
  }
}

{
  "error": {
    "code": "SERVICE_UNAVAILABLE",
    "message": "Service temporarily unavailable.",
    "details": {}
  }
}