Dallas Mavericks guard Devin Harris didn’t take his good health for granted this summer. He took full advantage of it. A year after undergoing complicated toe surgery that sidelined him for the first half of last season, Harris made sure he got the most out of his healthy summer. If a group of Mavs was running the ramps in the parking garage across the street from the American Airlines Center, you could pretty much guarantee that the 31-year-old Harris would be there. Same goes for playing pickup games and working with new-age strength coach Jeremy Holsopple. Harris, who signed a deal this summer worth as much as $16 million over four years after playing for the veteran’s minimum last season, feels as physically prepared entering his 11th NBA campaign as he’s ever been. “It’s peace of mind, really,” Harris said. “This is the first summer that I’ve been completely healthy, that I’ve been able to just stay in one spot, not coming in and not knowing what to expect. Just to be able to come in and work hard day in and day out. … Going into the season full-strength rather than catch up to everybody else, I’m excited.”