Published Jul 31, 2023 02:49AM ET © Reuters. FILE PHOTO: Men work at a construction site of apartment buildings in Beijing, China, July 15, 2022. REUTERS/Thomas Peter/FILE PHOTO USD/CNY +0.50% Add to/Remove from Watchlist By Summer Zhen and Carolina Mandl HONG KONG/NEW YORK (Reuters) - For all the excitement whipped up in China's markets by the Politburo last week, foreign investors say policymakers' words will have to be matched by substantive action to clean up an ailing property sector before confidence recovers. The sector accounts for a quarter of China's economy, yet developers' debts are sliding deeper into distressed territory,...