feat: Update navigation menu with collection page links

Added all 10 new collection pages to admin navigation:
- Intelligence Library: Avatars, Variants, Geo, Spintax, Patterns
- Content Engine: Campaigns, Fragments, Headlines, Offers, Queue
- Production: Added Leads to menu

Organized navigation into logical groups for better UX

frontend/src/layouts/AdminLayout.astro

@@ -20,19 +20,31 @@ const navGroups = [
     ]
   },
   {
-    title: 'Intelligence Station',
+    title: 'Intelligence Library',
     items: [
-      { href: '/admin/content/avatars', label: 'Avatars', icon: 'users' },
-      { href: '/admin/content/geo_clusters', label: 'Geo Clusters', icon: 'map' },
-      { href: '/admin/content/spintax_dictionaries', label: 'Spintax', icon: 'puzzle' },
-      { href: '/admin/content/cartesian_patterns', label: 'Patterns', icon: 'hub' },
+      { href: '/admin/intelligence/avatars', label: 'Avatar Intelligence', icon: 'users' },
+      { href: '/admin/collections/avatar-variants', label: 'Avatar Variants', icon: 'users' },
+      { href: '/admin/collections/geo-intelligence', label: 'Geo Intelligence', icon: 'map' },
+      { href: '/admin/collections/spintax-dictionaries', label: 'Spintax Dictionaries', icon: 'puzzle' },
+      { href: '/admin/collections/cartesian-patterns', label: 'Cartesian Patterns', icon: 'hub' },
     ]
   },
   {
-    title: 'Production Station',
+    title: 'Content Engine',
+    items: [
+      { href: '/admin/collections/campaign-masters', label: 'Campaigns', icon: 'web' },
+      { href: '/admin/collections/content-fragments', label: 'Content Fragments', icon: 'puzzle' },
+      { href: '/admin/collections/headline-inventory', label: 'Headlines', icon: 'puzzle' },
+      { href: '/admin/collections/offer-blocks', label: 'Offer Blocks', icon: 'puzzle' },
+      { href: '/admin/collections/generation-jobs', label: 'Generation Queue', icon: 'history' },
+    ]
+  },
+  {
+    title: 'Production',
     items: [
       { href: '/admin/sites', label: 'Sites & Deployments', icon: 'web' },
-      { href: '/admin/seo/articles', label: 'Generated Output', icon: 'newspaper' },
+      { href: '/admin/seo/articles', label: 'Generated Articles', icon: 'newspaper' },
+      { href: '/admin/leads', label: 'Leads & Inquiries', icon: 'users' },
       { href: '/admin/media/templates', label: 'Media Assets', icon: 'image' },
     ]
   },