Bring 2 cups water and quinoa to a boil in a saucepan. Reduce heat to medium-low, cover, and simmer until quinoa is tender, 15 to 20 minutes. Bring 1 1/2 cups water to a boil in a saucepan; remove from heat and stir couscous into the water. Cover saucepan and let stand until water is absorbed completely, about 10 minutes. Fluff couscous with a fork. Combine quinoa, couscous, chickpeas, tomatoes, red bell peppers, celery, cranberries, pecans, shallots, parsley, and cilantro. Combine lemon juice, curry paste, soy sauce, sugar, sesame oil, cumin, and salt in a blender; blend until smooth. Slowly pour olive oil into the blender while it is still running until dressing is emulsified. Pour dressing over quinoa-couscous mixture and toss to coat.