LOS ANGELES — How do you become introduced to PinkPantheress? Is it the viral, U.K. garage-sampling TikTok hits “Break It Off” or “Pain”? And as of Friday, it’s culminated in “Heaven Knows.” The debut full-length record from the U.K. star, who keeps her real name hidden, features 13 tracks she also co-produced. “Heaven Knows” is sometimes hyperpop, sometimes ornamented with …