migrate gitops-demo to generic chart

gitops-demo/dev/values.yaml

@@ -0,0 +1,15 @@
+# gitops-demo, dev environment — the ENTIRE per-service config now.
+# This replaces the old gitops-demo/dev/{deployment,service,ingress}.yaml:
+# three hand-written manifests collapse into these few lines. The shared
+# charts/app chart turns this into the same Deployment + Service + Ingress.
+name: gitops-demo
+
+image:
+  repository: traefik/whoami
+  tag: latest
+
+replicas: 1
+
+ingress:
+  host: gitops-demo.dev.lgkentang.com
+  clusterIssuer: letsencrypt-prod