Add a standalone tool that creates virtual AVB talker/listener endpoints
visible in the PipeWire graph (e.g. Helvum). Uses the loopback transport
so no AVB hardware or network access is needed.
The sink node consumes audio silently, the source produces silence.
Supports --milan flag for Milan v1.2 mode and --name for custom node
name prefix.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
