Actress Lori Loughlin has officially filed for divorce from fashion designer Mossimo Giannulli, bringing an end to one of Hollywood’s long-standing marriages after nearly 28 years together. Court records filed in Los Angeles Superior Court show that Loughlin submitted divorce documents on September 4, citing irreconcilable differences as the reason for ending the marriage. The filing provides new details about the couple’s separation and confirms that they had been living apart for more than a year before…