Implement profile management (task 14)

- Add updateProfile and updatePassword server actions
- Add getUserProfile function with sensitive data protection
- Create ProfileForm component for name and email updates
- Create PasswordChangeForm component with current password verification
- Create profile page at /profile with all profile management features
- Add profile and invitations navigation links to main page
- Implement email uniqueness validation
- Implement password hashing on password change

Requirements: 7.1, 7.2, 7.3, 7.4, 7.5

app/page.tsx

@@ -3,17 +3,38 @@ import ListCard from '@/components/ListCard'
 import NewListButton from '@/components/NewListButton'
 import GlobalSearch from '@/components/GlobalSearch'
 import EmptyState from '@/components/EmptyState'
+import Link from 'next/link'
+import { auth } from '@/auth'
 
 export const dynamic = 'force-dynamic'
 
 export default async function Home() {
   const lists = await getLists()
+  const session = await auth()
 
   return (
     <main className="container mx-auto px-4 sm:px-6 py-6 sm:py-8 max-w-7xl">
       <div className="flex flex-col sm:flex-row items-start sm:items-center justify-between gap-4 mb-6 sm:mb-8">
         <h1 className="text-2xl sm:text-3xl lg:text-4xl font-bold text-gray-900">Ultimate Lists</h1>
-        <NewListButton />
+        <div className="flex items-center gap-3">
+          {session?.user && (
+            <>
+              <Link
+                href="/invitations"
+                className="px-3 py-2 text-sm text-gray-700 hover:text-gray-900 hover:bg-gray-100 rounded-lg transition-colors"
+              >
+                Invitations
+              </Link>
+              <Link
+                href="/profile"
+                className="px-3 py-2 text-sm text-gray-700 hover:text-gray-900 hover:bg-gray-100 rounded-lg transition-colors"
+              >
+                Profile
+              </Link>
+            </>
+          )}
+          <NewListButton />
+        </div>
       </div>
 
       {/* Global Search */}