feat: add n8n Helm chart for Kubernetes on Raspberry Pi (ARM64)

- n8nio/n8n 2.19.2 (multi-arch, linux/arm64 ready)
- Single-container deployment with persistent storage
- SQLite default / PostgreSQL option
- Basic auth, encryption key via Secret
- Ingress, HPA, PDB, NetworkPolicy support
- Gitea CI: weekly auto-update + release workflow

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

templates/service.yaml

@@ -0,0 +1,19 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ include "n8n.fullname" . }}
+  labels:
+    {{- include "n8n.labels" . | nindent 4 }}
+  {{- with .Values.service.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+spec:
+  type: {{ .Values.service.type }}
+  ports:
+    - port: {{ .Values.service.port }}
+      targetPort: {{ .Values.service.targetPort }}
+      protocol: TCP
+      name: http
+  selector:
+    {{- include "n8n.selectorLabels" . | nindent 4 }}