Upgrade Tailwind CSS to v4 and migrate class usage

[roydigerhund]

This pull request upgrades Tailwind CSS from version 3 to version 4.

I ran the official Tailwind CSS v3 → v4 migration script to automatically update class names where possible.

Due to the dynamic color generation in the config file, I kept it in JS instead of migrating it to the new optional CSS config style.

[vercel]

@roydigerhund is attempting to deploy a commit to the zitadel Team on Vercel.

A member of the Team first needs to authorize it.

[roydigerhund]

@hifabienne is there anything I can do to get this approved and merged?

[hifabienne]

Hi @roydigerhund
@peintnermax is already assigned as a reviewer. I don't have an eta when this will be done.
But he will definitely look into it.