feat(vms): onboard UniFi OS Server as a KubeVirt VM on a non-gating track

First KubeVirt VM app + first real CDI http import. UniFi OS Server (UOS) is
Ubiquiti's current self-host product (the .deb is deprecated); it bundles UniFi
OS + Network app + its own datastore, so no MongoDB companion.

- apps/vms/unifi: CDI DataVolume (Ubuntu 24.04 cloud image -> longhorn-vm
  RWX/Block, live-migratable) + VirtualMachine (evictionStrategy: LiveMigrate)
  with cloud-init that installs podman/slirp4netns/jq and runs the UOS installer
  NON-INTERACTIVELY. The installer URL is resolved at boot from Ubiquiti's public
  firmware API (fw-update.ui.com/api/firmware-latest) — always-latest, no pinned
  URL to maintain (currently UOS v5.1.37).
- L4 exposure: two LoadBalancer Services (TCP+UDP) sharing a pinned, L2-announced
  Cilium VIP 192.168.1.54 (device inform/adoption + STUN can't ride the L7
  Gateway); external-dns publishes unifi.home.keithjackson.dev. UI on :11443.
- default-deny + additive CNPs (controller ingress, egress, and CDI-importer
  egress for the image pull).
- clusters/base/apps-vms.yaml: NON-GATING Flux Kustomization (wait:false,
  dependsOn platform-config) — VMs are a separate lifecycle from the app waves,
  so a slow VM import/install can't stall the app tier.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

apps/vms/unifi/kustomization.yaml

@@ -0,0 +1,13 @@
+---
+# UniFi OS Server VM (KubeVirt). Part of the non-gating `apps-vms` Flux Kustomization.
+# 90-httproute-optional.yaml is intentionally omitted (optional L7 UI; needs BackendTLSPolicy —
+# UOS serves HTTPS on :11443; browser access is via the L4 LoadBalancer VIP for now).
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - namespace.yaml
+  - 10-default-deny.yaml
+  - 20-datavolume.yaml
+  - 30-virtualmachine.yaml
+  - 40-networkpolicy.yaml
+  - 50-service-l4.yaml