Deal with string/int conversion when validating variables

[finestructure]

  contacts:
    url: ${api_url}/contacts/
    validation:
      status: 200
      json:
        # contacts are listed in reverse order or creation
        1:
          user: ${alice data.id}

The db field is an integer while the resolved variable substitution comes in as a string, leading to a failure:

❌  contacts FAILED : json invalid: index '1' validation error: key 'user' validation error: (2) is not equal to ("2")