Kristie Le made a spontaneous decision last weekend to get her first tattoo. That it would be for a good cause made her more adamant.  At the Black Needle Tattoo shop near Lake Merritt, she scanned her options — flowers, animals, fish, a skeletal hand — all drawn by students from Oakland School for the Arts. Choosing a goat to match her Vietnamese zodiac sign, she mustered the courage to have a needle etch the design on her inner left…