Should I list my work as dissertation or conference paper?
In a CV you try to organize your important personal information in a clear and useful way for others to see and gain a good perspective. In this case you have a thesis. It should clearly be listed so that it is clear it is one of the outcomes of your degree. It is commonplace for people to turn a thesis into papers but that usually involves rewriting the material substantially. Such papers will be listed under headings such as, for example, "Peer-reviewed articles", "Conference contributions", "Abstracts", etc. In your case you could add your article under a heading such as "Conference contributions", Non-reviewed articles" or "Other articles" (the later only makes sense if you have a heading "Peer-reviewed articles") and make sure it is clear that the heading also implies the articles are not peer reviewed.

If your article and your thesis is, in fact practically the same text with the same title, it would not be advisable to follow the guidelines outlined above. the reason is that it may seem to a reader of the CV as if you are trying to inflate your publication record. In that case you could perhaps make a note in the CV in conjunction with the thesis that it has also been published under the same name or to add it under a different heading but stating that the paper is the same as the thesis, thereby taking the possible edge of the double appearance.

In the end it is clearly not a problem to publish thesis material after a degree and still count both the thesis and the resulting article but the basic rule is that a specific text should not be counted twice. It would then essentially count as self-plagiarism. So just act responsibly and be open and honest about issues that can cause confusion or raise eye-brows.