Both your examples (is my number prime, are my XML nodes unique) are easily expressed in a dependently-typed language.
Dependent type checkers may be hard to implement, but the typing rules are fairly simple, and people have been using this correct by construction philosophy using dependently-typed languages for a while now.
I love the idea, although it doesn't seem to perform very smoothly, even on simple examples. A related project is Penrose [^1], except the latter isn't interactive.
The problem is not solved by using unsigned ints though, because it stems from integer overflow. I'm afraid your implementations are, alas, also incorrect.
Their point was about having to pay to export your data. Afaik Bridge is still to this day only available to paying users. Still, their statement is no longer true since exporting in bulk is permitted for free with the Import-Export app.
Briefly looking at the files and code it's hard to tell whether that is still the case, but it's fair to assume Import-Export would reuse most of the machinery behind Bridge.
Absolutely perplexed by the other answers that think CSS grid is a hammer for every nail. In your example without a table, you can just drop `display grid` and set `div {min-height: 33vh}`.