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/communication-rooms/[id]/messages/route.ts

@@ -0,0 +1,143 @@
+import { NextResponse } from 'next/server';
+import { db } from '@/lib/db';
+import { getSession } from '@/lib/auth';
+
+export async function GET(
+  request: Request,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const session = await getSession();
+    if (!session) {
+      return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+    }
+
+    const { id } = await params;
+    const room = await db.communicationRoom.findUnique({ where: { id } });
+
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 });
+    }
+
+    const role = session.user?.role;
+    const userId = session.userId;
+
+    // Access control
+    if (role === 'STUDENT' && room.studentId !== userId) {
+      return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+    } else if (role === 'TEACHER' && room.teacherId !== userId) {
+      return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+    } else if (role === 'PARENT') {
+      const parentLink = await db.parentStudentLink.findFirst({
+        where: { parentId: userId, studentId: room.studentId },
+      });
+      if (!parentLink) {
+        return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+      }
+    } else if (role === 'SCHOOL_ADMIN' || role === 'VICE_PRINCIPAL') {
+      if (room.schoolId !== session.user?.schoolId) {
+        return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+      }
+    }
+
+    const { searchParams } = new URL(request.url);
+    const page = parseInt(searchParams.get('page') || '1');
+    const limit = parseInt(searchParams.get('limit') || '50');
+    const skip = (page - 1) * limit;
+
+    const [messages, total] = await Promise.all([
+      db.communicationMessage.findMany({
+        where: { roomId: id },
+        orderBy: { createdAt: 'asc' },
+        skip,
+        take: limit,
+        include: {
+          sender: { select: { id: true, firstName: true, lastName: true, role: true } },
+        },
+      }),
+      db.communicationMessage.count({ where: { roomId: id } }),
+    ]);
+
+    // Mark messages as read for the current user
+    await db.communicationMessage.updateMany({
+      where: {
+        roomId: id,
+        senderId: { not: userId },
+        isRead: false,
+      },
+      data: { isRead: true },
+    });
+
+    return NextResponse.json({ messages, total, page, limit });
+  } catch (error) {
+    console.error('CommunicationMessage GET error:', error);
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
+  }
+}
+
+export async function POST(
+  request: Request,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const session = await getSession();
+    if (!session) {
+      return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+    }
+
+    const { id } = await params;
+    const room = await db.communicationRoom.findUnique({ where: { id } });
+
+    if (!room) {
+      return NextResponse.json({ error: 'Room not found' }, { status: 404 });
+    }
+
+    const role = session.user?.role;
+    const userId = session.userId;
+
+    // Only student and teacher can send messages (not admin, not parent)
+    if (role !== 'STUDENT' && role !== 'TEACHER') {
+      return NextResponse.json({ error: 'Only participants can send messages' }, { status: 403 });
+    }
+
+    if (room.studentId !== userId && room.teacherId !== userId) {
+      return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
+    }
+
+    if (room.status !== 'active') {
+      return NextResponse.json({ error: 'Room is not active' }, { status: 400 });
+    }
+
+    const body = await request.json();
+    const { content, messageType, fileUrl, metadata } = body;
+
+    if (!content && !fileUrl) {
+      return NextResponse.json({ error: 'Content or fileUrl is required' }, { status: 400 });
+    }
+
+    const message = await db.communicationMessage.create({
+      data: {
+        roomId: id,
+        senderId: userId,
+        content: content || '',
+        messageType: messageType || 'text',
+        fileUrl: fileUrl || null,
+        metadata: metadata || null,
+      },
+      include: {
+        sender: { select: { id: true, firstName: true, lastName: true, role: true } },
+      },
+    });
+
+    // Update room's updatedAt
+    await db.communicationRoom.update({
+      where: { id },
+      data: { updatedAt: new Date() },
+    });
+
+    return NextResponse.json(message, { status: 201 });
+  } catch (error) {
+    console.error('CommunicationMessage POST error:', error);
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
+  }
+}