feat: Add admin experiment management pages and components

- Implemented ExperimentPage for viewing and editing individual experiments.
- Created ExperimentsAdminPage for managing all experiments with a list and a modal for creating new experiments.
- Developed AnnotatePage for annotating experiments with different views based on annotation tools.
- Added CreateExperimentModal for creating new experiments with dataset selection.
- Introduced DeleteExperimentButton for confirming and executing experiment deletions.
- Built EditableExperimentHeader for editing experiment details.
- Created ExperimentsList component to display a list of experiments with links to their details.

src/app/annotate/[experimentId]/page.tsx

@@ -0,0 +1,74 @@
+import { redirect, notFound } from 'next/navigation';
+import { headers } from 'next/headers';
+import Link from 'next/link';
+import { auth } from '@/lib/auth';
+import { getAnnotationEntries } from '@/app/actions/annotations';
+import SingleChoiceView from '@/components/AnnotationViews/SingleChoiceView';
+import { getExperimentById } from '@/app/actions/experiment';
+
+interface Props {
+  params: Promise<{ experimentId: string}>;
+}
+
+export default async function AnnotatePage({ params }: Props) {
+  const session = await auth.api.getSession({ headers: await headers() });
+  if (!session) redirect('/user/sign-in');
+
+  const { experimentId: experimentIdStr } = await params;
+  const experimentId = parseInt(experimentIdStr, 10);
+  const prototype = await getExperimentById(experimentId).then(exp => exp?.annotationTool || null);
+
+  if (isNaN(experimentId)) {
+    return (
+      <div className="max-w-xl mx-auto py-16 text-center">
+        <p className="text-gray-600">Ungültige Experiment-ID.</p>
+        <Link href="/" className="text-blue-600 hover:underline mt-4 inline-block">
+          ← Startseite
+        </Link>
+      </div>
+    );
+  }
+
+
+  const entries = await getAnnotationEntries(experimentId);
+
+  if (entries.length === 0) {
+    return (
+      <div className="max-w-xl mx-auto py-20 text-center">
+        <div className="text-5xl mb-4">✓</div>
+        <h1 className="text-2xl font-bold text-green-600 mb-3">
+          Alle Samples bewertet!
+        </h1>
+        <p className="text-gray-600 mb-8">
+          Sie haben alle Samples in diesem Experiment bereits bewertet. Danke für Ihre Mitarbeit!
+        </p>
+        <Link
+          href="/"
+          className="px-6 py-3 bg-blue-600 hover:bg-blue-700 text-white font-semibold rounded-lg transition-colors"
+        >
+          Zurück zur Startseite
+        </Link>
+      </div>
+    );
+  }
+
+  // Render based on prototype type
+  const renderAnnotationView = () => {
+    switch (prototype) {
+      case 'single-choice':
+        return <SingleChoiceView entries={entries} experimentId={experimentId} />;
+      // Add more prototypes here as needed
+      default:
+        return (
+          <div className="max-w-xl mx-auto py-16 text-center">
+            <p className="text-gray-600">Unbekannter Annotation-Typ: {prototype}</p>
+            <Link href="/" className="text-blue-600 hover:underline mt-4 inline-block">
+              ← Startseite
+            </Link>
+          </div>
+        );
+    }
+  };
+
+  return renderAnnotationView();
+}