Combine the water, salt, and olive oil in a medium saucepan over medium-high heat and bring to a boil. Add the couscous and stir well. Cover and remove from the heat. Let stand 5 minutes, then toss gently with a fork. Let cool completely, tossing occasionally to ensure even cooling.
Combine the cooled couscous in a large stainless steel or other nonreactive bowl with the carrots, bell pepper, celery, onion, apple, cucumber, raisins, pine nuts, green onions, and cilantro.
Combine the ingredients for the dressing in a lidded jar and shake well to blend. Pour the dressing over the couscous mixture and toss to coat evenly. Taste and adjust seasoning if necessary. Let stand 30 minutes at room temperature before serving.
Makes about 10 cups, 8 to 10 servings