The 19-year-old singer-songwriter’s The Precipice is full of heart—and full of promise, too. “I don’t know where I’m going to,” Eliza Rhinelander sings on “Massachusetts,” the earnest and clear-voiced opener to the Halifax singer-songwriter’s debut album, The Precipice. “And I’ve never had this much to lose.” Given the 19-year-old folk singer’s trajectory this past year—from a crowdfunded EP to a sold-out show at The Carleton earlier this month—it would seem Rhinelander has at least once answer, or rather, a clear direction: upward…