chore: upgrade tailwind from v3 to v4

[GuilhermePSF]

Quick description

Upgrades the project to Tailwind v4 and updates configs and components accordingly.

Changes

• Upgrade Tailwind dependency to v4
• Migrate CSS config to the new v4 CLI format
• Update esbuild and Tailwind profiles from :safira to :default (seems to be standard 🤷)
• Replace deprecated ring-opacity-5 with ring-black/5

Notes

• Some classes might not be applying as expected (hard to confirm)
• Please do a more thorough QA to catch any issues

Edit: Icons now work, but it is generating CSS classes for each one of the 3000+ icons, and so performance takes a big hit. Suggestions on how to resolve this would be appreciated.

[enricoprazeres]