kvm2: record the review validation, enable the provider entry, changelog

Closes out the review-fix campaign. The kvm2 provider was deployed
in-cluster and validated against beelink -- the first time any of this
code had run against real libvirt rather than the in-memory fake.

config/manager/providers_config.yaml ships the kvm2-home entry enabled,
since the operator is now running it for real.

review/ carries the code review the four H-commits reference, so H1..H4
resolve to something rather than dangling: scope, the seven-chunk sweep,
the escalations, the ten deep dives and the final report. .claude/agents
carries the two reviewer definitions that produced them.

What the validation did not prove is recorded next to what it did: H2's
error paths need a body that fails part way through, and a healthy 433 MB
download never finishes short, so the unverified libvirtd short-stream
behaviour is still open. The kvm2 integration test has also still never
been run.

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

config/manager/providers_config.yaml

@@ -56,32 +56,32 @@ data:
       # made by kvm, so delete those Proxies first. It caches its base images
       # under base-<entry>-<key>.<format>, so it downloads its own copy rather
       # than sharing kvm's; budget the pool space. See docs/kvm2-provider.md.
-      # - name: kvm2-home
-      #   type: kvm2
-      #   kvm2:
-      #     sshKeyFile: /etc/proxy-operator/kvm/id_ed25519
-      #     knownHostsFile: /etc/proxy-operator/kvm/known_hosts
-      #     # insecureIgnoreHostKey: true
-      #     # diskSizeGb: 10
-      #     # installGuestAgent: false
-      #     # vendorData: |
-      #     #   #cloud-config
-      #     #   ...
-      #     images:
-      #       debian-13:
-      #         url: https://cloud.debian.org/images/cloud/trixie/latest/debian-13-generic-amd64.qcow2
-      #         # sha256: "<64 hex>"
-      #         # firmware: uefi
-      #       ubuntu-24.04:
-      #         url: https://cloud-images.ubuntu.com/noble/current/noble-server-cloudimg-amd64.img
-      #     machineTypes:
-      #       small:  {vcpus: 1, memoryMiB: 1024}
-      #       medium: {vcpus: 2, memoryMiB: 2048}
-      #     hosts:
-      #       - name: beelink
-      #         address: beelink.tail8c69c.ts.net:22
-      #         user: novakj
-      #         bridge: br0
-      #         # socket: /var/run/libvirt/libvirt-sock
-      #         # pool: default
+      - name: kvm2-home
+        type: kvm2
+        kvm2:
+          sshKeyFile: /etc/proxy-operator/kvm/id_ed25519
+          knownHostsFile: /etc/proxy-operator/kvm/known_hosts
+          # insecureIgnoreHostKey: true
+          # diskSizeGb: 10
+          # installGuestAgent: false
+          # vendorData: |
+          #   #cloud-config
+          #   ...
+          images:
+            debian-13:
+              url: https://cloud.debian.org/images/cloud/trixie/latest/debian-13-generic-amd64.qcow2
+              # sha256: "<64 hex>"
+              # firmware: uefi
+            ubuntu-24.04:
+              url: https://cloud-images.ubuntu.com/noble/current/noble-server-cloudimg-amd64.img
+          machineTypes:
+            small:  {vcpus: 1, memoryMiB: 1024}
+            medium: {vcpus: 2, memoryMiB: 2048}
+          hosts:
+            - name: beelink
+              address: beelink.tail8c69c.ts.net:22
+              user: novakj
+              bridge: br0
+              # socket: /var/run/libvirt/libvirt-sock
+              # pool: default