Fix ESLint configuration, fix errors, add as GitHub action

[jmccand]

Describe what you are trying to do
Fix the misconfigured ESLint and fix all current errors in ESLint, and make it a GitHub Action that runs on push and pull, so that all frontend code will be linted.

Steps for review

1. Try changing something (removing a type, removing dependencies in useEffect, ...).
2. npm run lint.

[williamschen23]

Overall I'd reconsider some of the missing dependency arrays. Some of them do make sense excluding, which is why personally id rather disable the eslint rule (or warning) over trying to fix them

[williamschen23]

since token never changes, we shouldnt useMemo it. In react 19.2, there is an useEventEffect function that seems to be perfect for this. In addition, we don't need to fix all the dependency array issues since they are warnings and not errors.

[jmccand]

Will change. I pass --max-warnings=0, so it doesn't tolerate warnings.

[williamschen23]

eslint github actions doesnt fail on warnings i thought?

[jmccand]

I think by default it doesn't, but if you pass --max-warnings it will.

[williamschen23]

do we want to enforce 0 warnings? I feel like sometimes the warnings are fine as react dependency arrays don't really need some of the dependencies eslint is hinting at