MEMPHIS — For decades, this storied American city has watched companies come but mostly go, its vacant storefronts and blighted buildings a reminder of its days as a thriving manufacturing hub and the painful decline that followed as those jobs vanished.As Paul Young, the city’s mayor, puts it, Memphis has been “the city people forgot about.”Then last summer, Memphis landed what Young and local business leaders called the city’s largest corporate investment in a generation — a “transformative” development for a place that has struggled to convince outsiders of its continued potential.The project was something every city dreams of, Young...