fix(migration): preserve VM MAC address during virtual-machine to vm-instance migration

Kube-OVN reads MAC address exclusively from the pod annotation
ovn.kubernetes.io/mac_address, not from the IP resource spec.macAddress.
Without pod-level annotations, migrated VMs receive a new random MAC,
breaking OS-level network config that matches by MAC (e.g. netplan).

Add a Helm lookup for the Kube-OVN IP resource in the vm-instance chart
template. When the IP resource exists, its macAddress and ipAddress are
automatically injected as pod annotations. This removes the need for
fragile Flux postRenderers on the HelmRelease — the chart itself handles
MAC/IP preservation based on actual cluster state.

Remove the postRenderers approach from migration 29 since the chart now
handles this natively.

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Kirill Ilin <stitch14@yandex.ru>
(cherry picked from commit 9a4f49238c)

packages/apps/vm-instance/templates/vm.yaml

@@ -34,6 +34,12 @@ spec:
     metadata:
       annotations:
         kubevirt.io/allow-pod-bridge-network-live-migration: "true"
+        {{- $ovnIPName := printf "%s.%s" (include "virtual-machine.fullname" .) .Release.Namespace }}
+        {{- $ovnIP := lookup "kubeovn.io/v1" "IP" "" $ovnIPName }}
+        {{- if $ovnIP }}
+        ovn.kubernetes.io/mac_address: {{ $ovnIP.spec.macAddress | quote }}
+        ovn.kubernetes.io/ip_address: {{ $ovnIP.spec.ipAddress | quote }}
+        {{- end }}
       labels:
         {{- include "virtual-machine.labels" . | nindent 8 }}
     spec: