Rewrite with wxt

Tested to work on Ditto, Primal (+ DMs), Universes. Should be okay with mkstack apps. NIP-04 and NIP-44 enc/dec also work. This new project uses React, Tanstack Query, and TailwindCSS. Everything seems to work but needs some polishing and testing. Also as @sam_thomson pointed out, should look into securing the stored secret key.

To test, clone this branch, npm i, npm run dev. the dev task launches chromium, and dev:firefox (pretty self-explanatorily) launches Firefox. Both are working as far as I can tell. I'm not super happy with the state of the codebase since basically all the UI is vibe-coded atm but we can make it work with a little TLC