feat: Round 21 - Major feature additions

- Schlaukopf.de clone: Subject Content Management System (7 categories, 416 topics)
- AI Integration: Pollination AI, OpenAI, Anthropic (chat, image/video generation)
- Virtual Character System: 5 animated characters (Owl, Dragon, Robot, Cat, Wizard)
- Illness Reporting with Parent Approval: privacy-first, student reports need parent approval
- Student-Teacher Communication Rooms: real-time chat, voice, file sharing
- Counseling/Guidance System: 4 types, calendar integration
- Disciplinary Committee System: case management, severity levels
- AI Test Generation: auto-generate practice tests before exams
- Teacher Grading Review: AI-powered grading audit
- VICE_PRINCIPAL role with same privileges as SCHOOL_ADMIN
- Class responsible teacher (Klassenlehrer) field
- 15 new Prisma models (80+ total)
- 30+ new API route files
- 8 new frontend components
- 400+ i18n keys
- Professional styling with gradient headers, animated counters, skeleton loading

src/app/api/grading-reviews/route.ts

@@ -0,0 +1,157 @@
+import { NextResponse } from 'next/server';
+import { db } from '@/lib/db';
+import { getSession } from '@/lib/auth';
+import ZAI from 'z-ai-web-dev-sdk';
+
+export async function GET(request: Request) {
+  try {
+    const session = await getSession();
+    if (!session) {
+      return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+    }
+
+    const { searchParams } = new URL(request.url);
+    const schoolId = searchParams.get('schoolId') ?? session.user?.schoolId;
+    const status = searchParams.get('status');
+
+    if (!schoolId) {
+      return NextResponse.json([]);
+    }
+
+    const role = session.user?.role;
+    if (role !== 'SCHOOL_ADMIN' && role !== 'SUPER_ADMIN' && role !== 'VICE_PRINCIPAL' && role !== 'TEACHER') {
+      return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+    }
+
+    const where: Record<string, unknown> = { schoolId };
+    if (status) where.status = status;
+
+    if (role === 'TEACHER') {
+      where.teacherId = session.userId;
+    }
+
+    const reviews = await db.teacherGradingReview.findMany({
+      where,
+      orderBy: { createdAt: 'desc' },
+      include: {
+        assessment: { select: { id: true, title: true } },
+        teacher: { select: { id: true, firstName: true, lastName: true } },
+        comments: {
+          include: {
+            user: { select: { id: true, firstName: true, lastName: true } },
+          },
+          orderBy: { createdAt: 'desc' },
+        },
+      },
+    });
+
+    return NextResponse.json(reviews);
+  } catch (error) {
+    console.error('GradingReviews GET error:', error);
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
+  }
+}
+
+export async function POST(request: Request) {
+  try {
+    const session = await getSession();
+    if (!session) {
+      return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+    }
+
+    const role = session.user?.role;
+    if (role !== 'SCHOOL_ADMIN' && role !== 'SUPER_ADMIN' && role !== 'VICE_PRINCIPAL') {
+      return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+    }
+
+    const body = await request.json();
+    const { schoolId, assessmentId, teacherId } = body;
+
+    if (!schoolId || !assessmentId || !teacherId) {
+      return NextResponse.json({ error: 'schoolId, assessmentId, and teacherId are required' }, { status: 400 });
+    }
+
+    // Get assessment results for the teacher
+    const assessment = await db.assessment.findUnique({
+      where: { id: assessmentId },
+      include: {
+        results: {
+          where: { teacherId },
+          include: {
+            student: { select: { id: true, firstName: true, lastName: true } },
+          },
+        },
+      },
+    });
+
+    if (!assessment) {
+      return NextResponse.json({ error: 'Assessment not found' }, { status: 404 });
+    }
+
+    // Generate AI review
+    const systemPrompt = 'Du bist ein erfahrener Lehrer. Überprüfe die Benotung und gib Feedback. Prüfe auf Fairness und Konsistenz.';
+
+    const gradingData = assessment.results.map((r: { student: { firstName: string; lastName: string }; score: number | null; maxScore: number | null; grade: string | null }) => ({
+      student: `${r.student.firstName} ${r.student.lastName}`,
+      score: r.score,
+      maxScore: r.maxScore,
+      grade: r.grade,
+    }));
+
+    let reviewResult: string;
+    let discrepanciesFound = 0;
+
+    try {
+      const ai = await ZAI.create();
+      const response = await ai.chat.completions.create({
+        messages: [
+          { role: 'system', content: systemPrompt },
+          {
+            role: 'user',
+            content: `Überprüfe die folgende Benotung und gib Feedback zu Fairness und Konsistenz:\n\n${JSON.stringify(gradingData, null, 2)}`,
+          },
+        ],
+      });
+
+      reviewResult = response?.choices?.[0]?.message?.content || 'Review could not be generated';
+    } catch (aiError) {
+      console.error('AI review error:', aiError);
+      reviewResult = JSON.stringify({
+        overall: 'AI review could not be generated. Manual review recommended.',
+        fairness: 'unknown',
+        consistency: 'unknown',
+        recommendations: ['Please review grading manually'],
+      });
+    }
+
+    // Count discrepancies
+    const scores = assessment.results
+      .map((r: { score: number | null; maxScore: number | null }) => r.score && r.maxScore ? (r.score / r.maxScore) * 100 : null)
+      .filter((s: number | null): s is number => s !== null);
+    if (scores.length > 0) {
+      const avg = scores.reduce((a: number, b: number) => a + b, 0) / scores.length;
+      discrepanciesFound = scores.filter((s: number) => Math.abs(s - avg) > 30).length;
+    }
+
+    const review = await db.teacherGradingReview.create({
+      data: {
+        schoolId,
+        assessmentId,
+        teacherId,
+        aiProvider: 'pollination',
+        status: 'completed',
+        reviewResult,
+        discrepanciesFound,
+      },
+      include: {
+        assessment: { select: { id: true, title: true } },
+        teacher: { select: { id: true, firstName: true, lastName: true } },
+      },
+    });
+
+    return NextResponse.json(review, { status: 201 });
+  } catch (error) {
+    console.error('GradingReviews POST error:', error);
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
+  }
+}