The American job market is clawing its way back — steadily if slowly — from the devastation inflicted by the coronavirus-caused recession. What no one knows is just how long it might take for workers to be made whole. In October, the government said Friday, employers added 638,000 jobs. It was a solid gain, more than economists had expected. And it was even stronger than the headline number suggested. Yet even with last month’s hiring, the economy has regained barely 12 million of the 22 million jobs it lost in March and April, when the virus suddenly paralyzed much of the economy. Now, a surge of confirmed infections to record highs — which could accelerate as the weather gets colder — threatens the tentative economic comeback. So does Congress’ failure to provide another jolt of aid for individuals and businesses now that a multi-trillion-dollar financial rescue […]