Add the shared NIC dispatcher that owns the underlying VirtualNic tunnel.
Connect member ring tunnels through a private member table.
Track reverse flow ownership from packets written by a member.
Replies read from the shared device go back to the same member.
Packets without an owner fall back to any active member.
Mark the shared NIC invalid when the underlying tunnel closes or fails.
Notify members so their NicCtx can rebuild.
sijie.sun