Whatever happened to recovery summer? This was supposed to be the season the economy heated up, thanks to a wave of public works projects, funded by the government’s stimulus program. But summer is coming to an end, and the recovery has not taken root. (The Labor Department on Friday reported a slight rise in the unemployment rate to 9.6 percent in August as more people were looking for work.) And before long, stimulus dollars will be fading like autumn leaves. None of that is encouraging for President Obama, who launched the summer with a crew in hard hats in Columbus, Ohio, on June 18. “Today, I return to Columbus to mark a milestone on the road to recovery: the 10,000th project launched under the Recovery Act,” Obama said, announcing a $15 million effort to widen a roadway and add bike lanes.