Alma Sanchez knew that much of the housing available to low-wage workers in West Marin, many of them Latinos, was substandard. But she was shocked by what she found while interviewing participants in a sweeping new study of the region’s urgent housing needs. “Dignified housing in West Marin seems unreachable to many of our residents,” Ms. Sanchez said. “The houses are filled with mold. There are rusty pipes. Let’s not even talk about the quality…