Is a clear, silicone waterproof sealant said to be safe for aquariums also going to be safe to come into contact with food?

Once cured, yes, perfectly safe.

Once silicone is set up it’s probably safe.

I’m not sure how different the silicone used to make some cookware is from what you are talking about....

check the specific grade as many silicon caulks and sealants are not designed for continual water immersion; most non-pigmented (clear) silicone products are food contact safe if they are allowed to fully cure.

Aquarium safe silicone usually says on the back, "safe for food contact when cured and washed" or something similar. 100% silicone is generally fine, it is the mold inhibitors and additives in bathroom sealants that cause the toxicity problems.

you are not a fish. do not use that stuff in a food situation