offer to refactor the react app

[joshribakoff]

I see some places I can improve the react app.

as one example, using sets & maps is intuitive for programmers used to systems programming but can be an anti-pattern in react, which expects immutability. Normally, we stick to arrays and objects -- and if we really need sets and maps there are libraries like ImmerJS

I can make a PR, I can add tests (playwright + vitest) too.

[cjpais]

Happy to review at the very least and decide from there. If you can do each in a separate PR where it makes sense it would be great so I can review

[joshribakoff]

ty for your time #527