Test with explicit host labels in registration

Added --labels flag to registration command:
- Explicitly specify host execution during registration
- Should override any container-based execution
- Testing if Docker daemon errors are finally resolved

🤖 Generated with [Claude Code](https://claude.ai/code)

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

forgejo-runner-helm/templates/serviceaccount.yaml

@@ -0,0 +1,12 @@
+{{- if .Values.serviceAccount.create -}}
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ include "forgejo-runner.serviceAccountName" . }}
+  labels:
+    {{- include "forgejo-runner.labels" . | nindent 4 }}
+  {{- with .Values.serviceAccount.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+{{- end }}