BEIJING/SHANGHAI, Dec 8 (Reuters) - Manufacturers and eateries keen to stay open in China are preferring to err on the side of caution, by retaining COVID-19 curbs until they get a clearer picture of just how workplaces will be affected by the easing of stringent measures. The world's second largest economy is bracing for a wave of infections as it relaxes a "zero-COVID" policy, winding down a campaign of hunting out and isolating infections as it hands back to individuals most of the task of detection and treatment. In sparse comments on workplace conditions, however, national health officials have urged...