Ok, I’ll say it. Often, when a vegan restaurant opens, only those who prefer to dine animal-product-free have much cause to rejoice. Not so with True Bistro, an upscale vegan eatery that opened in Somerville’s Teele Square this fall. Here, dietary principles don’t trump flavor. A foodie runs the kitchen, and the result is that even the most skeptical carnivore will likely never miss the meat. Add to that a spare, gray-on-white décor so calming that it’s spa-like and reasonable prices, and you could go either way here: it’s elegant enough for a special night out and affordable enough to nab a …