An Optimus robot in front of a Cybertruck in Alameda, California, on Aug. 23.Anadolu via Getty ImagesTesla shareholders just overwhelmingly backed CEO Elon Musk’s unprecedented pay package that could be worth $1 trillion over a decade, but engineers running the company’s main vehicle programs, for its top-selling Model Y, Model 3 and the controversial Cybertruck, aren’t sticking around to see how things turn out.Emmanuel Lamacchia, an eight-year Tesla veteran and program manager for the Model Y, said late S ...