fix: auto-detect N8N_SECURE_COOKIE from Ingress/TLS settings

Set N8N_SECURE_COOKIE=true only when ingress.enabled=true AND ingress.tls
is configured. All other cases (LoadBalancer, HTTP Ingress) default to false,
eliminating the secure cookie error without manual configuration.

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

templates/deployment.yaml

@@ -73,6 +73,12 @@ spec:
               name: {{ .Values.n8n.basicAuth.existingSecret | default (include "n8n.fullname" .) }}
               key: {{ .Values.n8n.basicAuth.passwordKey }}
         {{- end }}
+        - name: N8N_SECURE_COOKIE
+          {{- if and .Values.ingress.enabled .Values.ingress.tls }}
+          value: "true"
+          {{- else }}
+          value: "false"
+          {{- end }}
         - name: EXECUTIONS_DATA_PRUNE
           value: {{ .Values.n8n.executions.pruneData | quote }}
         - name: EXECUTIONS_DATA_MAX_AGE