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.spec.ts

@@ -0,0 +1,55 @@
+import { AuditLogService } from './audit-log.service';
+import { PrismaService } from '../prisma/prisma.service';
+
+describe('AuditLogService', () => {
+  let service: AuditLogService;
+  let prisma: {
+    auditLog: { create: jest.Mock; findMany: jest.Mock };
+  };
+
+  beforeEach(() => {
+    prisma = {
+      auditLog: {
+        create: jest.fn(),
+        findMany: jest.fn().mockResolvedValue([]),
+      },
+    };
+    service = new AuditLogService(prisma as unknown as PrismaService);
+  });
+
+  it('record writes the entity type, action, and actor', async () => {
+    await service.record({
+      entityType: 'Colony',
+      entityId: 'colony-1',
+      action: 'CREATE',
+      userId: 'user-1',
+    });
+
+    const [[createArg]] = prisma.auditLog.create.mock.calls as [
+      [
+        {
+          data: {
+            entityType: string;
+            entityId: string;
+            action: string;
+            userId?: string;
+          };
+        },
+      ],
+    ];
+    expect(createArg.data.entityType).toBe('Colony');
+    expect(createArg.data.entityId).toBe('colony-1');
+    expect(createArg.data.action).toBe('CREATE');
+    expect(createArg.data.userId).toBe('user-1');
+  });
+
+  it('findAll filters by entity type and id', async () => {
+    await service.findAll({ entityType: 'Colony', entityId: 'colony-1' });
+
+    const [[queryArg]] = prisma.auditLog.findMany.mock.calls as [
+      [{ where: { entityType?: string; entityId?: string } }],
+    ];
+    expect(queryArg.where.entityType).toBe('Colony');
+    expect(queryArg.where.entityId).toBe('colony-1');
+  });
+});