auto-claude: subtask-2-2 - Simplify client-side auth check in DashboardContent

Removed redundant client-side authentication logic since server-side
protection is now in place (middleware + page-level checks). The
component now:
- No longer performs useEffect auth check on mount
- No loading state for authentication
- Renders dashboard content immediately
- Maintains logout functionality
- Assumes user is authenticated (guaranteed by server)

This eliminates the flash of loading state and improves UX while
maintaining security through server-side protection.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/components/auth/DashboardContent.tsx

@@ -1,11 +1,9 @@
 'use client';
 
-import { useEffect, useState } from 'react';
 import { useRouter } from 'next/navigation';
-import { Loader2, BarChart2, Users, Eye, Clock, TrendingUp, TrendingDown, LogOut } from 'lucide-react';
+import { BarChart2, Users, Eye, Clock, TrendingUp, TrendingDown, LogOut } from 'lucide-react';
 import { useTranslations, useLocale } from 'next-intl';
 import { createClient } from '@/lib/supabase/client';
-import type { User } from '@supabase/supabase-js';
 
 interface MetricCard {
   title: string;
@@ -20,25 +18,6 @@ export default function DashboardContent() {
   const t = useTranslations('dashboard');
   const locale = useLocale();
   const router = useRouter();
-  const [user, setUser] = useState<User | null>(null);
-  const [loading, setLoading] = useState(true);
-
-  useEffect(() => {
-    const checkAuth = async () => {
-      const supabase = createClient();
-      const { data: { user } } = await supabase.auth.getUser();
-
-      if (!user) {
-        router.push(`/${locale}/login`);
-        return;
-      }
-
-      setUser(user);
-      setLoading(false);
-    };
-
-    checkAuth();
-  }, [locale, router]);
 
   const handleLogout = async () => {
     const supabase = createClient();
@@ -46,25 +25,6 @@ export default function DashboardContent() {
     router.push(`/${locale}`);
   };
 
-  if (loading) {
-    return (
-      <div className="min-h-screen flex items-center justify-center">
-        <div className="flex flex-col items-center space-y-4">
-          <Loader2 className="h-8 w-8 text-zinc-400 animate-spin" />
-          <p className="text-zinc-400 text-sm">{t('status.loading')}</p>
-        </div>
-      </div>
-    );
-  }
-
-  if (!user) {
-    return (
-      <div className="min-h-screen flex items-center justify-center">
-        <p className="text-zinc-400">{t('status.notAuthenticated')}</p>
-      </div>
-    );
-  }
-
   const metrics: MetricCard[] = [
     {
       title: t('metrics.pageViews.title'),