The Laguna Grill closed at 3:30 pm the day we visited.
The snack stations are open until park close, though, so you can still get hot pretzels and other items for the last couple of hours. But the snack offerings are not what I would consider supper.
To maximize your meals, your best bet would be to arrive in time for an early breakfast, eat lunch as soon as lunch is served (11 am, IIRC) and then eat again (if you still have stomach capacity!!) right before the Grill closes up shop. The downfall with that plan.....that's extra time eating and less time enjoying the park.