As Samwise Gamgee put it in “Lord of the Rings: The Two Towers,” “Po-ta-toes. Boil ’em, mash ’em, put ’em in a stew.” Carbondale is taking that advice to heart for its 117th annual Potato Days, which returns Oct. 2-4 with a locally sourced harvest lunch and an emphasis on supporting Western Slope agriculture. This year’s theme, “Get Your Kicks on Root 66,” puts an emphasis on supporting local agriculture and sourcing the festival’s main meal fro…