feat(backend): Audit-Log-Abfrage (Modul 19)

AuditModule um GET /audit-log?entityType=&entityId= erweitert
(nur Administrator). Zusaetzlich Jest-E2E-Parallelitaet begrenzt
(maxWorkers: 4), um wiederkehrende Verbindungsengpaesse gegen
Postgres unter vielen parallelen Testsuiten zu vermeiden.

ApiCore-Backend/src/audit/audit-log.service.ts

@@ -1,6 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import { PrismaService } from '../prisma/prisma.service';
-import { AuditAction, Prisma } from '../../generated/prisma';
+import { AuditAction, AuditLog, Prisma } from '../../generated/prisma';
 
 interface RecordAuditLogInput {
   entityType: string;
@@ -11,6 +11,11 @@ interface RecordAuditLogInput {
   afterData?: unknown;
 }
 
+export interface AuditLogFilter {
+  entityType?: string;
+  entityId?: string;
+}
+
 @Injectable()
 export class AuditLogService {
   constructor(private readonly prisma: PrismaService) {}
@@ -27,4 +32,12 @@ export class AuditLogService {
       },
     });
   }
+
+  async findAll(filter: AuditLogFilter = {}): Promise<AuditLog[]> {
+    return this.prisma.auditLog.findMany({
+      where: { entityType: filter.entityType, entityId: filter.entityId },
+      orderBy: { timestamp: 'desc' },
+      take: 200,
+    });
+  }
 }