A disputed land-use strategy designed to protect new developments from devastation in the county's exurban, fire-prone areas appears to have passed its first and most critical test this week. As the Witch Creek fire raced through some of San Diego County's priciest neighborhoods and crept to the edge of others north and east of Rancho Santa Fe, not a single home in the five subdivisions that have implemented the strategy was lost, fire authorities said. The communities, which together cover hundreds of acres, are The Bridges, The Crosby, Cielo, Santa Fe Valley and 4S Ranch. Officials with the Rancho Santa...