kvm2: integration test, sample Proxy, providers-config entries and Makefile target

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

config/manager/manager.yaml

@@ -149,9 +149,10 @@ spec:
         - name: providers-config
           mountPath: /etc/proxy-operator
           readOnly: true
-        # SSH material for kvm providers (sshKeyFile / knownHostsFile in the
-        # providers config point here). Optional: the mount is empty when the
-        # Secret does not exist, and only kvm entries need it. Create it with:
+        # SSH material for the kvm and kvm2 providers (sshKeyFile /
+        # knownHostsFile in the providers config point here). One Secret
+        # serves both types. Optional: the mount is empty when the Secret
+        # does not exist, and only kvm and kvm2 entries need it. Create it with:
         #   kubectl -n egress-proxies-operator-system create secret generic kvm-ssh \
         #     --from-file=id_ed25519=<private key> \
         #     --from-file=known_hosts=<known_hosts with every host's key>
@@ -167,6 +168,7 @@ spec:
       - name: providers-config
         configMap:
           name: providers-config
+      # Shared by the kvm and kvm2 providers; see the mount above.
       - name: kvm-ssh
         secret:
           secretName: kvm-ssh