Couldn’t fly back to Washington, D.C., last week for the “Leader of the Pack’s” festivities? Missed out on last weekend’s inaugural gala in Sacramento? (Don’t feel badly, so did Arnie.) Forget the Pelosi and Schwarzenegger soirees, and head on over to Democratic Assemblywoman Mary Hayashi’s district office grand opening from 4 to 6:30 p.m. Jan. 12. The office is at 22320 Foothill Blvd., suite 540, in the shadow of Hayward’s former 11-story City Hall. Eat, drink and be merry, if the “light refreshments” on the menu are your forte.