feat: Round 22 - Exam calendar, parent portal, teacher grading, deep styling

- Exam calendar integration: Plan Exam button, countdown badges, exam filter
- Parent portal: Children overview, illness approvals, grades, attendance
- Teacher grading: Stylus annotation, AI review, bulk grading mode
- Deep schlaukopf crawling: AI-powered content extraction from schlaukopf.de
- Dashboard: Upcoming exams, AI tips section
- Settings: AI provider config, virtual character toggle, management tabs
- Layout: Favorites section, notification badges on sidebar items
- Auth: VICE_PRINCIPAL demo account, feature showcase
- Attendance: Illness report integration
- Assessments: Plan exam button, AI test generation
- Fixed schoolId auto-detect in counseling and disciplinary APIs
- Added MessageSquare import to settings-view
- 150+ new i18n keys

src/app/api/grading/annotate/route.ts

@@ -0,0 +1,111 @@
+import { NextResponse } from 'next/server';
+import { z } from 'zod';
+import { db } from '@/lib/db';
+import { getSession } from '@/lib/auth';
+
+const saveAnnotationSchema = z.object({
+  assessmentId: z.string().min(1),
+  studentId: z.string().min(1),
+  annotationData: z.string().min(1),
+  annotationImage: z.string().optional(),
+});
+
+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 assessmentId = searchParams.get('assessmentId');
+    const studentId = searchParams.get('studentId');
+
+    if (!assessmentId || !studentId) {
+      return NextResponse.json({ error: 'assessmentId and studentId are required' }, { status: 400 });
+    }
+
+    const result = await db.assessmentResult.findUnique({
+      where: {
+        assessmentId_studentId: { assessmentId, studentId },
+      },
+      select: {
+        id: true,
+        annotationData: true,
+        annotationImage: true,
+        note: true,
+        score: true,
+      },
+    });
+
+    if (!result) {
+      return NextResponse.json({ annotation: null });
+    }
+
+    return NextResponse.json({
+      annotation: result.annotationData ? {
+        id: result.id,
+        annotationData: result.annotationData,
+        annotationImage: result.annotationImage,
+      } : null,
+    });
+  } catch (error) {
+    console.error('Grading Annotate 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 !== 'TEACHER' && role !== 'SCHOOL_ADMIN' && role !== 'SUPER_ADMIN' && role !== 'VICE_PRINCIPAL') {
+      return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+    }
+
+    const body = await request.json();
+    const parsed = saveAnnotationSchema.safeParse(body);
+    if (!parsed.success) {
+      return NextResponse.json(
+        { error: 'Validation failed', details: parsed.error.issues },
+        { status: 400 }
+      );
+    }
+
+    const { assessmentId, studentId, annotationData, annotationImage } = parsed.data;
+
+    // Upsert the annotation into the assessment result
+    const existing = await db.assessmentResult.findUnique({
+      where: { assessmentId_studentId: { assessmentId, studentId } },
+    });
+
+    if (existing) {
+      const updated = await db.assessmentResult.update({
+        where: { id: existing.id },
+        data: {
+          annotationData,
+          annotationImage: annotationImage ?? existing.annotationImage,
+        },
+      });
+      return NextResponse.json({ annotation: { id: updated.id, annotationData: updated.annotationData, annotationImage: updated.annotationImage } });
+    } else {
+      // Create a new result with just the annotation
+      const created = await db.assessmentResult.create({
+        data: {
+          assessmentId,
+          studentId,
+          annotationData,
+          annotationImage: annotationImage ?? null,
+        },
+      });
+      return NextResponse.json({ annotation: { id: created.id, annotationData: created.annotationData, annotationImage: created.annotationImage } }, { status: 201 });
+    }
+  } catch (error) {
+    console.error('Grading Annotate POST error:', error);
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
+  }
+}