ATLANTA — The Georgia Supreme Court has upheld the authorization of up to $397 million in bonds to build a new baseball stadium for the Braves in Cobb County. Three Cobb County residents opposed the authorization and appealed a Cobb County Superior Court ruling approving the bond issuance to the high court. In the unanimous opinion published Monday, Justice David Nahmias wrote that an intergovernmental contract used to authorize the bonds is valid.