feat: add eslint to the project

[43081j]

This introduces ESLint along with the typescript and lit plugins.

It also changes any code currently producing a lint error.

Was poking around the repo and noticed this wasn't already here. Let me know if it was an active choice to not have a lint script and i'll close this PR

FYI the import.meta.env types come from vite. may be fine but would break if a consumer ever removed vite i suppose