Growth in China’s services sector picked up in June while big Japanese companies planned to ramp up spending at the fastest pace in a decade, offering hope that prospects are improving for Asia’s largest economies despite sluggish factory growth. Wednesday’s data fueled expectations that the wobbly global economy may start leveling out in the second half of the year, but the outlook remains murky, with fears that Greece’s debt crisis could splinter the euro zone and worries about whether China can avoid a stock market crash keeping investors on edge.