chore: upgrade to Tailwind v4 and Vite v8

[LuggaPugga]

This PR aims to modernize the codebase:

• Migrate to Tailwind v4 and replace SCSS with Tailwind colors
• Update Vite to v8

I could also switch Prettier and ESLint to OxFmt and Oxlint, but I wanted to check with you first.

Before merging, we should wait for the next Vite release so we don’t need the Rolldown override due to: rolldown/rolldown#8808

If you see any issues or want any changes, just let me know :)

[JovannMC]

note: this is a boilerplate response for numerous open PRs

hiya!

firstly sorry for the late response to your PR (if it has been open for a while). we are closing this, along with other people's PRs, as we are preparing for the very overdue update drop. once merged, it will most likely break most existing PRs and will need to be redone. track the PR #282, and once merged you may wish to open another PR with the new base.

do also note this repository's and our main contributing guidelines which was made recently here, when submitting your new PR: repo & main