Should I differentiate between contract and full-time?

I call out contract/freelance work, and I believe custom dictates doing that, at least in the USA.

A potential employer should understand that short-term contracting requires different skills. Contractors generally have to start producing right away and also manage communications and “onboarding” themselves, while possibly juggling multiple commitments.

Interviewers may interpret a history of contract work as lack of commitment to an employer. You need to prepare to overcome that objection. Long-term contracting relationships look good.

Whether contract or full-time I emphasize the nature and success of the project and my part in it rather than my payroll status.

I do mention it on my CV (as part of the job title), but I'm not sure that it actually matters much. I figure that offering the clarification won't do any harm and might do at least a little good.

I haven't, though in reality almost none has been permanent for someone else.