The river hands this city two faces: soft green summers with freighters sliding past, and winters when the wind comes straight up off the water with nothing in its path. M Lawn & Snow answers both — mowing, edging and trimming while things are growing, plowing, shoveling and salting once they stop. The name says about as much as the work does, which is a fair sign of how it gets done. A lawn kept level all season and a driveway cleared ahead of the commute are two quiet versions of the same attention. Detroit rewards that kind of steadiness, right around the calendar.