feat: Grundgeruest fertigstellen (Backend/Frontend/K8s)

Backend: Prisma-Client auf prisma-client-js + Driver-Adapter (@prisma/adapter-pg)
umgestellt (Prisma 7 verlangt Adapter, ESM-Client brach an Jest), erste Migration
erzeugt und angewendet, /api/v1 Versioning, Swagger unter /api/v1/docs, Helmet,
globale ValidationPipe, PrismaModule, HealthModule (/health, /health/ready mit
DB-Check), tsconfig.build.json Root-Dir-Fix (dist/main.js statt dist/src/main.js).

Frontend: Tailwind v4 + shadcn/ui initialisiert, TanStack Query Provider, PWA
Manifest (app/manifest.ts), Vitest + Testing Library Setup, next.config output
standalone.

deploy/k8s: Dockerfiles (Backend/Frontend, Multi-Stage) + Deployment/Service/
Ingress/ConfigMap/Secret-Vorlagen fuer beide Projekte.

Lokale Dev-/Test-Postgres-Instanz unter ApiCore-Backend/.devdb angelegt (eigene
Rolle, kein bestehendes Passwort noetig), .env/.env.test lokal befuellt.

Lint, Typecheck, Tests und Build sind fuer Backend und Frontend gruen; Server
wurde lokal gestartet und /health, /health/ready, /api/v1/docs manuell verifiziert.

ApiCore-Backend/src/health/health.controller.spec.ts

@@ -0,0 +1,30 @@
+import { ServiceUnavailableException } from '@nestjs/common';
+import { HealthController } from './health.controller';
+import { PrismaService } from '../prisma/prisma.service';
+
+describe('HealthController', () => {
+  let controller: HealthController;
+  let prisma: { $queryRaw: jest.Mock };
+
+  beforeEach(() => {
+    prisma = { $queryRaw: jest.fn() };
+    controller = new HealthController(prisma as unknown as PrismaService);
+  });
+
+  it('liveness returns ok without touching the database', () => {
+    expect(controller.liveness()).toEqual({ status: 'ok' });
+    expect(prisma.$queryRaw).not.toHaveBeenCalled();
+  });
+
+  it('readiness returns ok when the database responds', async () => {
+    prisma.$queryRaw.mockResolvedValueOnce([{ '?column?': 1 }]);
+    await expect(controller.readiness()).resolves.toEqual({ status: 'ok' });
+  });
+
+  it('readiness throws ServiceUnavailableException when the database is unreachable', async () => {
+    prisma.$queryRaw.mockRejectedValueOnce(new Error('connection refused'));
+    await expect(controller.readiness()).rejects.toBeInstanceOf(
+      ServiceUnavailableException,
+    );
+  });
+});