refactor: migrar GitLab → Gitea (aulas 10, 11, 13)

- Aula 10: Gitea + Registry + Actions + Runner (substituiu GitLab)
  - gitea-values.yaml: PostgreSQL standalone, Valkey standalone, ~800Mi RAM
  - setup.sh/cleanup.sh: namespace gitea, Helm gitea-charts/gitea + actions
  - README.md: documentação completa com de→para (GitLab/Harbor/Tekton vs Gitea)

- Aula 11: ArgoCD (GitOps) — removido GitLab Runner (runner vive na aula-10)
  - setup.sh: só ArgoCD, integração SSH com Gitea
  - node-bugado/.gitea/workflows/ci.yml: pipeline convertida

- Aula 13: Container Factory — atualizado para Gitea
  - setup.sh/cleanup.sh: referências GitLab → Gitea
  - pipelines/postgresql/ci.yml: Gitea Actions workflow
  - README.md: conexão com act_runner explicada

- CLAUDE.md: tabela de aulas atualizada

aula-13/k8s/postgresql/service.yaml

@@ -0,0 +1,18 @@
+# =============================================================================
+# Service - PostgreSQL
+# =============================================================================
+apiVersion: v1
+kind: Service
+metadata:
+  name: postgresql
+  labels:
+    app: postgresql
+spec:
+  type: ClusterIP
+  ports:
+    - port: 5432
+      targetPort: 5432
+      protocol: TCP
+      name: postgresql
+  selector:
+    app: postgresql