fix: resolve TypeScript compilation errors in core service

- Add twoFactorEnabled to LoginResponse user type
- Replace useBodyParser with express json() middleware for body limit

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/core-service/src/core/auth/auth.service.ts

@@ -28,6 +28,7 @@ interface LoginResponse {
     firstName: string;
     lastName: string;
     role: string;
+    twoFactorEnabled: boolean;
   };
   requiresTwoFactor?: boolean;
 }

packages/core-service/src/main.ts

@@ -3,6 +3,7 @@ import { ValidationPipe, Logger } from '@nestjs/common';
 import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
 import cookieParser from 'cookie-parser';
 import helmet from 'helmet';
+import { json } from 'express';
 import { AppModule } from './app.module';
 
 async function bootstrap(): Promise<void> {
@@ -16,7 +17,7 @@ async function bootstrap(): Promise<void> {
   app.use(cookieParser());
 
   // Body size limit erhoehen fuer Base64 Avatar-Uploads (Standard ~100KB)
-  app.useBodyParser('json', { limit: '1mb' });
+  app.use(json({ limit: '1mb' }));
 
   // CORS
   const corsOrigins = process.env.CORS_ORIGINS?.split(',') ?? [