fix: remove unused prisma import causing DATABASE_URL error in CI

src/__tests__/unit/permissions.test.ts

@@ -7,7 +7,6 @@
 import { describe, test, expect, mock, beforeEach } from 'bun:test';
 import { hasRole, canManageTournament, canCreateTournaments } from '@/lib/permissions';
 import { getSession } from '@/lib/auth-simple';
-import { prisma } from '@/lib/prisma';
 import type { User } from '@prisma/client';
 
 // Create mock functions at module level