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/hpa.yaml

@@ -0,0 +1,32 @@
+{{- if .Values.autoscaling.enabled }}
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: {{ include "n8n.fullname" . }}
+  labels:
+    {{- include "n8n.labels" . | nindent 4 }}
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: {{ include "n8n.fullname" . }}
+  minReplicas: {{ .Values.autoscaling.minReplicas }}
+  maxReplicas: {{ .Values.autoscaling.maxReplicas }}
+  metrics:
+    {{- if .Values.autoscaling.targetCPUUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: {{ .Values.autoscaling.targetCPUUtilizationPercentage }}
+    {{- end }}
+    {{- if .Values.autoscaling.targetMemoryUtilizationPercentage }}
+    - type: Resource
+      resource:
+        name: memory
+        target:
+          type: Utilization
+          averageUtilization: {{ .Values.autoscaling.targetMemoryUtilizationPercentage }}
+    {{- end }}
+{{- end }}