WASHINGTON — Elon Musk's social media app X on Monday began offering its X Money banking service to all US subscribers of its paid Premium and Premium+ tiers, part of the multi-billionaire's ambition to turn the site into an "everything app." The rollout widens access to a product that had been available since late June as a test to a limited group of top-tier subscribers.X Money lets users hold deposits, send peer-to-peer payments, pay bills, transfer money by wire, and mail checks without leaving the X app. Deposits are held at Cross River Bank, a New Jersey-based lender that is...