Filters _get_node_network() to bridge/OVSBridge types only (excludes physical
NICs, bonds), plus SDN vnets from _get_sdn_vnets(). vlan_aware: Linux bridge
reflects its bridge_vlan_aware config flag; OVS bridge always true; SDN vnet
always false (VLAN already fixed by the vnet's zone/tag).
4 new tests: bridge/vnet filtering, Linux bridge vlan_aware flag, OVS bridge
always vlan_aware, SDN vnet never vlan_aware. All 15 tests in the file pass.
Test cases: single/dual NIC with VLAN tags or trunk config, per-NIC DHCP control,
disk resize parameter, snippet storage validation, IP wait timeout, destroy paths.
All TDD cases green.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>