Conservators in Istanbul are racing to safeguard scores of at-risk heritage sites in the wake of Turkey’s deadliest earthquake in modern history, bracing for the probability of an even greater disaster in a city straddling an active faultline.But the effort to protect the 8,000-year-old city’s treasures was already complicated by the country’s fractious politics, with the opposition-controlled municipal heritage department frequently at odds with culture authorities from president Recep Tayyip Erdoğan’s government.Istanbul’s Grand Çamlıca Mosque is one of around 35,000…