CEO Brian Chesky is spending hundreds of millions to relaunch his travel company as an everything app. Fitness! Food! Microdermabrasion? A WIRED exclusive.PHOTOGRAPH: GABRIELA HASBUNAs Brian Chesky tells it, the reinvention of Airbnb started with the coup at OpenAI. On November 17, 2023, the board of OpenAI fired company CEO Sam Altman. His friend Chesky leapt into action—publicly defending his pal on X, getting on the phone with Microsoft’s CEO, and throwing himself into the thick of Altman’s b...