San Francisco is having a civic nervous breakdown because the brother of President Donald Trump’s son-in-law is buying a minority stake in the Giants. Not Donald Trump. Not Jared Kushner. Joshua Kushner. And not control of the team. A minority stake . Apparently, that is enough to send parts of San Francisco’s activist and media culture into full panic mode. One Giants employee posted a video from Oracle Park turning in their uniform and quitting because Kushner was buying into the team. Social media lit up with complaints about “MAGA ownership” and Trump-world influence invading one of San Francisco’s most beloved civic institutions. San Francisco is having a civic nervous breakdown because the brother of President Donald Trump’s son-in-law is buying a minority stake in the Giants. Steven Hirsch One Giants employee posted a video from Oracle Park turning in their uniform and quitting because Kushner was buying into the team. Getty Images There is just one problem.…