fix: update Prisma client configuration and test files for Prisma 7.x compatibility

src/__tests__/e2e/csv-upload-deduplication.test.ts

@@ -5,11 +5,10 @@
  */
 
 import { test, expect } from '@playwright/test';
-import { PrismaClient } from '@prisma/client';
+import { prisma } from '@/lib/prisma';
 import fs from 'fs';
 import path from 'path';
 
-const prisma = new PrismaClient();
 
 test.describe('CSV Upload Player Deduplication', () => {
   let testTournamentId: number;