Just in time for the holiday-shopping homestretch, Panini Authentic is honoring its own No. 12, Indianapolis Colts superstar quarterback Andrew Luck, with a unique “12 Days of Luckmas” celebration on the company website. Each day from now until December 23, Panini Authentic will feature special holiday pricing on a different piece of unique autographed Luck memorabilia. Each day’s special will be good for that day only and…