fix: remove legacy tailwind.config.js conflicting with Nuxt UI v3

Nuxt UI v3 manages Tailwind v4 internally. The old tailwind.config.js
pointed to src/ and used Tailwind v3 format, causing SSR conflicts.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tailwind.config.js

@@ -1,7 +0,0 @@
-/** @type {import('tailwindcss').Config} */
-export default {
-  content: [
-    "./index.html",
-    "./src/**/*.{vue,js,ts,jsx,tsx}",
-  ],
-}