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/calendar-events/exams/route.ts

@@ -0,0 +1,150 @@
+import { NextResponse } from 'next/server';
+import { db } from '@/lib/db';
+import { getSession } from '@/lib/auth';
+import { differenceInCalendarDays } from 'date-fns';
+
+// ── GET: List upcoming exams ──────────────────────────────────────────
+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 ?? undefined;
+    const classGroupId = searchParams.get('classGroupId');
+    const limit = parseInt(searchParams.get('limit') ?? '20', 10);
+
+    if (!schoolId) {
+      return NextResponse.json({ error: 'schoolId is required' }, { status: 400 });
+    }
+
+    const now = new Date();
+
+    const where: Record<string, unknown> = {
+      schoolId,
+      eventType: 'exam',
+      date: { gte: now },
+    };
+
+    if (classGroupId) {
+      where.classGroupId = classGroupId;
+    }
+
+    // For students: only show exams from their classes
+    if (session.user?.role === 'STUDENT') {
+      const student = await db.student.findFirst({
+        where: { userId: session.userId },
+        select: { id: true },
+      });
+      if (student) {
+        const enrollments = await db.enrollment.findMany({
+          where: { studentId: student.id },
+          select: { classGroupId: true },
+        });
+        const classIds = enrollments.map((e) => e.classGroupId);
+        where.classGroupId = { in: classIds };
+      }
+    }
+
+    // For parents: show exams from their children's classes
+    if (session.user?.role === 'PARENT') {
+      const parentLinks = await db.parentStudentLink.findMany({
+        where: { parentId: session.userId },
+        select: { studentId: true },
+      });
+      const studentIds = parentLinks.map((l) => l.studentId);
+      const enrollments = await db.enrollment.findMany({
+        where: { studentId: { in: studentIds } },
+        select: { classGroupId: true },
+      });
+      const classIds = enrollments.map((e) => e.classGroupId);
+      where.classGroupId = { in: classIds };
+    }
+
+    const exams = await db.calendarEvent.findMany({
+      where,
+      include: {
+        subject: { select: { id: true, name: true } },
+        classGroup: { select: { id: true, name: true } },
+        teacher: { select: { id: true, firstName: true, lastName: true } },
+      },
+      orderBy: { date: 'asc' },
+      take: limit,
+    });
+
+    // Add countdown info
+    const enrichedExams = exams.map((exam) => {
+      const daysUntil = differenceInCalendarDays(new Date(exam.date), now);
+      return {
+        ...exam,
+        daysUntil,
+        countdownLabel: daysUntil === 0
+          ? 'today'
+          : daysUntil === 1
+            ? 'tomorrow'
+            : daysUntil < 7
+              ? `${daysUntil} days`
+              : `${Math.floor(daysUntil / 7)} weeks`,
+      };
+    });
+
+    return NextResponse.json(enrichedExams);
+  } catch (error) {
+    console.error('Exams GET error:', error);
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
+  }
+}
+
+// ── POST: Create an exam event ────────────────────────────────────────
+export async function POST(request: Request) {
+  try {
+    const session = await getSession();
+    if (!session) {
+      return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+    }
+
+    const userRole = session.user?.role;
+    if (userRole !== 'TEACHER' && userRole !== 'SCHOOL_ADMIN' && userRole !== 'VICE_PRINCIPAL' && userRole !== 'SUPER_ADMIN') {
+      return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+    }
+
+    const body = await request.json();
+    const {
+      title, date, startTime, endTime, subjectId, classGroupId,
+      notes, assessmentId, schoolId,
+    } = body;
+
+    if (!title || !date || !schoolId) {
+      return NextResponse.json({ error: 'title, date, and schoolId are required' }, { status: 400 });
+    }
+
+    const event = await db.calendarEvent.create({
+      data: {
+        schoolId,
+        teacherId: session.user?.id ?? '',
+        title,
+        date: new Date(date),
+        startTime: startTime || null,
+        endTime: endTime || null,
+        eventType: 'exam',
+        subjectId: subjectId || null,
+        classGroupId: classGroupId || null,
+        notes: notes || null,
+        allDay: !startTime && !endTime,
+        assessmentId: assessmentId || null,
+      },
+      include: {
+        subject: { select: { id: true, name: true } },
+        classGroup: { select: { id: true, name: true } },
+        teacher: { select: { id: true, firstName: true, lastName: true } },
+      },
+    });
+
+    return NextResponse.json(event, { status: 201 });
+  } catch (error) {
+    console.error('Exam POST error:', error);
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
+  }
+}