Seniors in retirement facilities and nursing homes countywide are being kept indoors, with their windows closed and away from outside activities due to the poor air quality today, administrators at local nursing homes said."We are providing our seniors indoor activities like videogames and cards," said Lynette Zaborowski, activities director at Hilltop Commons in Grass Valley. "They are not able to go our into the patio area. We also have a walking club, whose members won't be walking outside this afternoon."Yvonne Felker, a nurse at the Spring Hill Manor Rehabilitation and Convalescent Hospital in Grass Valley, said residents were "keeping the …