There are always indicators when a small Texas town is destined for something great. Duck confit pops up on a restaurant menu. A technology start-up moves in. And, at least in the case of Luling, the largest convenience store on the planet opens its doors. Sitting at the confluence of Interstate 10, U.S. 183, U.S. 90, and Texas Highway 80, this farming-and-ranching community celebrated its 150th anniversary this year, and its nickname—the Crossroads to Everywhere—feels particularly apt. Most tourists venture to Luling in pursuit of classic Central Texas barbecue or world-class watermelons, which, born of a fortuitous combination of loamy soil and unrelenting sunshine, grow here in motley abundance and have been celebrated for more than seventy years by townspeople—and now around 30,000 visitors—on the last…