Have you tried freeze dried snap peas like these?
Since they are actually veggies (unlike some other veggie-flavored snack foods), they are packed with the same good fiber and protein found in the raw vegetable.
Other healthy ideas are freeze dried or fresh fruit, yougurt and cheese sticks or wedges, and hummus or guacamole with whole grain pita or crackers. If your Child can have nuts at school, try small baggies of roasted unsalted nuts or make your own trail mix with nuts, dried fruit, whole grain cereal, etc.
As far as fresh veggies go, it is smart of you not to send them to school if you know he won’t eat them, but that doesn’t mean you should stop trying! Keep offering them as part of his after school snack and dinner. Eventually, he’ll find some he likes and you can start sending them in his lunch bag to round out the meal.