Fix: Remove broken getKlausurApiUrl and clean up empty lines

sed replacement left orphaned hostname references in story page
and empty lines in getApiBase functions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

admin-lehrer/app/(admin)/ai/test-quality/_components/MetricCard.tsx

@@ -0,0 +1,54 @@
+'use client'
+
+export function MetricCard({
+  title,
+  value,
+  subtitle,
+  trend,
+  color = 'blue',
+}: {
+  title: string
+  value: string | number
+  subtitle?: string
+  trend?: 'up' | 'down' | 'stable'
+  color?: 'blue' | 'green' | 'red' | 'yellow' | 'purple'
+}) {
+  const colorClasses = {
+    blue: 'bg-blue-50 border-blue-200',
+    green: 'bg-emerald-50 border-emerald-200',
+    red: 'bg-red-50 border-red-200',
+    yellow: 'bg-amber-50 border-amber-200',
+    purple: 'bg-purple-50 border-purple-200',
+  }
+
+  const trendIcons = {
+    up: (
+      <svg className="w-4 h-4 text-emerald-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 10l7-7m0 0l7 7m-7-7v18" />
+      </svg>
+    ),
+    down: (
+      <svg className="w-4 h-4 text-red-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 14l-7 7m0 0l-7-7m7 7V3" />
+      </svg>
+    ),
+    stable: (
+      <svg className="w-4 h-4 text-slate-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 12h14" />
+      </svg>
+    ),
+  }
+
+  return (
+    <div className={`rounded-xl border p-5 ${colorClasses[color]}`}>
+      <div className="flex items-start justify-between">
+        <div>
+          <p className="text-sm font-medium text-slate-600">{title}</p>
+          <p className="mt-1 text-2xl font-bold text-slate-900">{value}</p>
+          {subtitle && <p className="mt-1 text-xs text-slate-500">{subtitle}</p>}
+        </div>
+        {trend && <div className="mt-1">{trendIcons[trend]}</div>}
+      </div>
+    </div>
+  )
+}