PHILADELPHIA — Mehmet Oz barely goes a day on the campaign trail without someone questioning his ties to Pennsylvania. And now his home in suburban Philadelphia — the Republican Senate candidate’s biggest defense against questions about his residency — is making national news. A story from ABC News this week probed the unusual sale conditions around Oz’s family home near the upper-class Montgomery County enclave of Bryn Athyn, where his wife’s family has lived for generations. But there’s more to the story behind the manor than the strange terms of its acquisition. In August, The Philadelphia …