Add full-stack Hello World app with CI/CD

- Go backend with PostgreSQL connection
- Next.js frontend with TypeScript
- Docker Compose for local development
- Woodpecker CI pipeline for build and push
- Kubernetes manifests with Kustomize
- ArgoCD application for GitOps deployment

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

manifests/kustomization.yaml

@@ -0,0 +1,20 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+namespace: hell-world
+
+resources:
+  - namespace.yaml
+  - postgres-secret.yaml
+  - postgres-pvc.yaml
+  - postgres-deployment.yaml
+  - postgres-service.yaml
+  - backend-deployment.yaml
+  - backend-service.yaml
+  - frontend-deployment.yaml
+  - frontend-service.yaml
+  - ingress.yaml
+
+commonLabels:
+  app.kubernetes.io/name: hell-world
+  app.kubernetes.io/managed-by: kustomize