MIDDLEBURY — Every morning, when David Donahue walks through the doors at Eastview in Middlebury, he reminds himself of one simple fact. “This is their home,” he says. As executive director and CEO of Eastview, a senior retirement community in Middlebury, Donahue oversees nearly every aspect of the campus that houses 130 residents in 99 units. Tucked off South Street Extension, where wildflowers sway beside its walls and the Green Mountains rise…