feat(charts): add Helm chart for gitks Git bare repository service

- Create Chart.yaml with application metadata and keywords
- Add _helpers.tpl with name, fullname, labels, and DNS template functions
- Generate ConfigMap with all gitks configuration environment variables
- Implement StatefulSet with persistent volume claims for repository data
- Create headless service for pod DNS and cluster communication
- Add gRPC service for client connections and metrics service
- Include HorizontalPodAutoscaler for dynamic scaling
- Add PodDisruptionBudget to maintain cluster availability
- Create ServiceAccount with proper security context
- Add test connection pod using grpcurl for health checks
- Generate NOTES.txt with installation instructions and quick start guide
- Create .helmignore file to exclude common development files
- Configure persistence, resource limits, and security settings
- Add support for cluster mode with etcd service discovery

charts/templates/serviceaccount.yaml

@@ -0,0 +1,13 @@
+{{- if .Values.serviceAccount.create -}}
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ include "gitks.serviceAccountName" . }}
+  labels:
+    {{- include "gitks.labels" . | nindent 4 }}
+  {{- with .Values.serviceAccount.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+automountServiceAccountToken: {{ .Values.serviceAccount.automount }}
+{{- end }}