What happens if/when the McDonalds refuses to comply? What if the people DEMAND them contrary to this edict?
The City Attorney will go to court and get an injunction, and any store manager who sells a Happy Meal will be arrested for contempt of court and will go to jail.
What if the people DEMAND them contrary to this edict?
They can vote out the Board of Supervisors, or they can go to a McDonald's in neighboring Oakland. (From what I know of San Francisco, I think the latter is much more likely.)
Just to be a wiseass I would stand at the counter with a big bag of little toys and hand them to any kids who ordered a burger.
Just out of spite.