It’s permanent magic. Sandra Bullock debuted a meaningful tattoo at the “Practical Magic 2” premiere Wednesday. The actress, 62, has the letters “L” and “B” and the number “2” inked on her left shoulder, with Page Six Style confirming the dainty script is a tribute to her kids, Louis and Laila. The tattoo was on full display on the London red carpet, with Bullock opting for a strapless, leopard print Givenchy dress. She accessorized the corset gown, which featured a large bow at the waist, with layered diamond necklaces and black heels. Bullock wore her hair in loose waves and added strappy black heels. The film premiere was the Oscar…