Jamison “Jamie” Marra, president and CEO of Bellevue-based software development and consulting firm Singularity Partners, and his wife, Shannon Marra, are listing their Medina mansion for $7.56 million. The interior of this traditional home, a mix of classic-modern and vintage, was designed by Nate Berkus, and is the first project in Seattle to have the stamp of this famed philanthropic designer, author and gentle TV personality. Coldwell Banker Bain Vice President and Managing Broker Wendy…