If you're looking for a VS Code extension or a GitHub app, check out https://semanticdiff.com/. I'm a co-founder of this project.
If you prefer a CLI tool, check out https://github.com/Wilfred/difftastic. It supports more languages, but doesn't recognize when code has been replaced by an equivalent version ("invariances"). So it will show some changes (e.g. replacing a character in a string with an escape sequence) even though they are technically equivalent.
There seem to be built-in methods for serializing and deserializing crypto context as well as ciphertexts [0], so it shouldn't be too difficult to build a "complete" example that performs the actual computation in a different application. That said, with a duration of 7 seconds for a simple addition, it is still far from many practical applications, in my opinion.
If you prefer a CLI tool, check out https://github.com/Wilfred/difftastic. It supports more languages, but doesn't recognize when code has been replaced by an equivalent version ("invariances"). So it will show some changes (e.g. replacing a character in a string with an escape sequence) even though they are technically equivalent.