feat: menú Ads + Social; Drive por defecto en activos

Renombra Ad Tracker a Ads, añade módulo Social (perfiles RRSS)
y abre Biblioteca en pestaña Drive. Aclara histórico GSC en Orgánico.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/DashboardShell.tsx

@@ -16,6 +16,7 @@ import {
   CalendarDays,
   Radio,
   Megaphone,
+  Share2,
   Contact,
   Menu,
   X,
@@ -70,11 +71,18 @@ const NAV_ITEMS: NavItem[] = [
   },
   {
     href: '/dashboard/ad-tracker',
-    label: 'Ad Tracker',
+    label: 'Ads',
     icon: Megaphone,
     iconClass: 'text-violet-500',
     moduleId: 'ad-tracker',
   },
+  {
+    href: '/dashboard/social',
+    label: 'Social',
+    icon: Share2,
+    iconClass: 'text-fuchsia-500',
+    moduleId: 'social',
+  },
   {
     href: '/dashboard/organico',
     label: 'Orgánico',