Bummer. Some news for those returning to Shanghai from domestic travel. Via their official WeChat account the city announced that starting from midnight tonight, those returning to Shanghai from anywhere in China for the first five days are not allowed to enter public places such as restaurants, bars, shopping centers, supermarkets, food markets, beauty salons, bath, massage studios, gyms, Internet cafes, KTVs and all sorts of entertainment venues.
You are still allowed to go to work. From the sound of it, that's pretty much all you can do during that time.
You'll also be required to take a PCR test every day for the first 3 days, and another one on the 5th day. If that one is negative you can go back to your normal routine.
During those five days, your Health Code will apparently still be green, but show a notice saying you've recently been traveling.
But there might be some silver lining here. It could signal that Shanghai may be moving in a similar direction as Hong Kong, which has moved away from forcing people to quarantine and not leave a designated premise.