San Francisco (AFP) – Meta’s second most powerful executive Sheryl Sandberg made the shock announcement Wednesday she will leave after a 14-year tenure that included helping steer scandal-prone Facebook to advertising dominance. Sandberg, 52, has been one of the most influential women in Silicon Valley and her departure comes as the social media juggernaut faces an uncertain future and fierce competition. Her exit from Facebook parent Meta will be effective in the fall, she wrote on the platform, adding she planned to remain on the firm’s board. A Harvard-educated executive, Sandberg joined Fa…