As Freeport-McMoRan celebrates an arrangement to end a multi-year dispute with Indonesia over the giant Grasberg mine, investors are fretting over the costs.Shares in Phoenix-based Freeport fell the most among mining peers on Tuesday after the company said it reached an “understanding” with the government of Indonesia that will allow it to continue to operate its flagship copper-and-gold asset through 2041.Under the terms of the deal, Freeport will divest an additional 41.64 percent of PTFI,