Wildfires raging throughout California’s wine country have ravaged more than 170,000 acres and killed 21 people so far, with hundreds missing. The blazes are sending a cloud of ash and smoke over the bay, threatening residents with polluted air. On Tuesday, air quality officials issued health and smoke advisories for all nine Bay Area counties, the second such warning issued this fall wildfire season. Residents should avoid outdoor activities, close windows and doors, and avoid using air-conditioning units, according to…