Does working with a visa that contradicts the type of work in a Muslim country—such as the visa being for a "laborer" while the work is as a "sales representative," "accountant," or "doctor"—constitute a violation of Islamic law?

The laws governing work, which the ruler establishes for the benefit of the country and its people, must be adhered to and observed. It is his right to restrict what is permissible if he sees a legitimate benefit in doing so. Whatever contains public benefit must be complied with, both inwardly and outwardly.