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/_helpers.tpl

@@ -0,0 +1,74 @@
+{{/*
+Expand the name of the chart.
+*/}}
+{{- define "n8n.name" -}}
+{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Create a default fully qualified app name.
+*/}}
+{{- define "n8n.fullname" -}}
+{{- if .Values.fullnameOverride }}
+{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- $name := default .Chart.Name .Values.nameOverride }}
+{{- if contains $name .Release.Name }}
+{{- .Release.Name | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
+{{- end }}
+{{- end }}
+{{- end }}
+
+{{/*
+Create chart name and version as used by the chart label.
+*/}}
+{{- define "n8n.chart" -}}
+{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Common labels
+*/}}
+{{- define "n8n.labels" -}}
+helm.sh/chart: {{ include "n8n.chart" . }}
+{{ include "n8n.selectorLabels" . }}
+{{- if .Chart.AppVersion }}
+app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
+{{- end }}
+app.kubernetes.io/managed-by: {{ .Release.Service }}
+{{- end }}
+
+{{/*
+Selector labels
+*/}}
+{{- define "n8n.selectorLabels" -}}
+app.kubernetes.io/name: {{ include "n8n.name" . }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+{{- end }}
+
+{{/*
+Create the name of the service account to use
+*/}}
+{{- define "n8n.serviceAccountName" -}}
+{{- if .Values.serviceAccount.create }}
+{{- default (include "n8n.fullname" .) .Values.serviceAccount.name }}
+{{- else }}
+{{- default "default" .Values.serviceAccount.name }}
+{{- end }}
+{{- end }}
+
+{{/*
+Name of the secret holding the encryption key and auth credentials
+*/}}
+{{- define "n8n.secretName" -}}
+{{- .Values.n8n.existingSecret | default (include "n8n.fullname" .) }}
+{{- end }}
+
+{{/*
+Name of the PVC for n8n data
+*/}}
+{{- define "n8n.pvcName" -}}
+{{- .Values.persistence.existingClaim | default (include "n8n.fullname" .) }}
+{{- end }}