By Brenda Goh and Yimou Lee SHANGHAI/TAIPEI (Reuters) – Hundreds of workers joined protests at Foxconn’s flagship iPhone plant in China, with some men smashing surveillance cameras and windows, footage uploaded on social media showed. The rare scenes of open dissent in China mark an escalation of unrest at the massive factory in Zhengzhou city that has come to symbolise a dangerous build-up in frustration with the country’s ultra-severe COVID rules as well as inept handling of the situation by the world’s largest contract manufacturer. The trigger for the protests, which began early on Wednesd…