Deploy Tailscale operator on ringtail k3s cluster (#215)

## Summary
- Extract shared Tailscale operator resources (CRDs, RBAC, Deployment, ProxyClass, DNSConfig) into `tailscale-operator-base/` so both clusters reference the same manifests
- Add `tailscale-operator-ringtail/` overlay with 1-replica ProxyGroup and ExternalSecret for the shared OAuth client
- Add ArgoCD Application targeting `ringtail.tail8d86e.ts.net:6443`
- Update `.yamllint.yaml` ignore path for the moved `operator.yaml`

## Deployment and Testing
- [ ] Sync `apps` app to pick up the new Application definition
- [ ] `argocd app sync tailscale-operator-ringtail`
- [ ] Verify ExternalSecret syncs: `kubectl --context=k3s-ringtail -n tailscale get externalsecret`
- [ ] Verify operator pod runs: `kubectl --context=k3s-ringtail -n tailscale get pods`
- [ ] Verify ProxyGroup ready: `kubectl --context=k3s-ringtail -n tailscale get proxygroups`
- [ ] Verify indri operator still works: `argocd app diff tailscale-operator`
- [ ] Check Tailscale admin for new operator device with `tag:k8s-operator`

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

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/215

pulumi/tailscale/policy.hujson

@@ -158,7 +158,7 @@
 		"tag:feed": ["autogroup:admin", "tag:blumeops"],
 		"tag:registry": ["autogroup:admin", "tag:blumeops"],
 		"tag:k8s-api": ["autogroup:admin", "tag:blumeops"],
-		"tag:k8s-operator": ["autogroup:admin", "tag:blumeops"],
+		"tag:k8s-operator": ["autogroup:admin", "tag:blumeops", "tag:k8s-operator"],
 		"tag:k8s": ["autogroup:admin", "tag:blumeops", "tag:k8s-operator"],
 		"tag:ci-gateway": ["autogroup:admin", "tag:blumeops"],
 		"tag:flyio-proxy": ["autogroup:admin", "tag:blumeops"],