Kelp and shellfish are to be avoided with hyper because of their high iodine content. Any food high in iodine ought to be avoided since iodine is one of the building blocks of thyroid hormones and being hyper, you don't need too much available.
Foods that contain goitrogens (substances that can inflame the thyroid) are questionable. I think the reason you find so much contradiction out there is because not a lot is known...oh, there are plenty of theories on nutrition, but not much fact. What helps one person may be anathema to another.
My rule has always been "If it bothers you, avoid it; if it doesn't and it's good for you, have at it." Many of us have found we haven't had to alter our diets a bit in deference to thyroid disease.
So, I don't think you're going to find the definitive list anywhere. Go with what most agree on (e.g. avoid iodine), and beyond that, eat a good, healthy, well-blanced diet.