Heidi Klum celebrated the inaugural HeidiFest—a Bavarian festival in Munich, Germany—with her and ex-husband Seal’s kids Leni, 21, Henry, 20, Johan, 18, and Lou, 15. For Heidi Klum, a haus is not a home without her kids.  That’s why the Project Runway host wants her and ex Seal‘s four children—Leni Klum, 21, Henry Samuel, 20, Johan Samuel,…