⚡ Upgrade tailwind version to 4

[HassanZahirnia]

No description provided.

[steven-fox]

Overall, looks very good to me, Hassan! Thank you!

Only minor things I saw:

1. Noticed the vite config was not changed to include the @tailwindcss/vite plugin, but you've informed that is not necessary.
2. We should add styling to the base css to make buttons have a pointer cursor again.

@layer base {
  button:not(:disabled),
  [role="button"]:not(:disabled) {
    cursor: pointer;
  }
}