Add an interactive 3D weather-journey landing page for Abrban at the site root.

Replace the root redirect with a scroll-driven three.js scene that flies from
overcast clouds through rain and a thunderstorm into a clear blue sunny sky,
fronted by Persian/RTL marketing sections. The dashboard at /dashboard is
untouched.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/tailwind.config.ts

@@ -8,6 +8,9 @@ const config: Config = {
   ],
   theme: {
     extend: {
+      fontFamily: {
+        vazir: ['var(--font-vazir)', 'system-ui', 'sans-serif'],
+      },
       colors: {
         primary: {
           50: '#eff6ff',