samples: a kvm2 crawl pool, not just the single-proxy sample

proxy_kvm2.yaml shows one VM; nothing showed the shape a crawler actually
leases from. Add a five-Proxy pool on the kvm2-home entry: four share one
labelled cloud-init Secret, and the fifth carries its own inline block
because it runs squid on 8080 and spec.port has to match the http_port a
shared Secret would pin.

It stays out of the samples kustomization so `apply -k config/samples`
doesn't boot a pool along with the one-per-provider samples. All six
objects validate against the installed CRD under --dry-run=server.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

config/samples/kustomization.yaml

@@ -1,6 +1,9 @@
 ## Append samples of your project ##
 # providers-config.yaml is deliberately absent: it is a sample
 # --providers-config file, not a Kubernetes manifest.
+# proxy_kvm2_crawl_pool.yaml is deliberately absent too: it is a whole pool
+# of VMs, so it stays an explicit `kubectl apply -f` rather than something
+# `apply -k` boots along with the one-per-provider samples.
 resources:
 - proxy_kubernetes.yaml
 - proxy_gcp.yaml