chore: strengthen backend eslint profile

src/common/dto-validation.spec.ts

@@ -1,4 +1,5 @@
 import { BadRequestException, ValidationPipe } from '@nestjs/common';
+
 import { CredentialsDto } from '../modules/auth/presentation/auth.dto';
 import {
   CreateBankCardDto,
@@ -6,7 +7,8 @@ import {
 } from '../modules/banking/bank-cards/presentation/bank-card.dto';
 
 describe('DTO validation', () => {
-  const pipe = new ValidationPipe({ transform: true, whitelist: true });
+  const pipe = new ValidationPipe({
+    forbidUnknownValues: true, transform: true, whitelist: true });
 
   it('requires credentials and normalizes a valid email', async () => {
     const metadata = { type: 'body' as const, metatype: CredentialsDto };