Respawn the channel's head+fader loopbacks and re-issue its routes (task #68).
The head-node input ports the source(s) link into, or undefined for an unknown channel.
Every channel strip in the mix.
The channel's patched source endpoint(s) — empty when unpatched.
The channel's fader (linear) — 0 means the operator pulled it down.
Individual mute OR an active mute group — an operator-silenced channel.
The mixer surface the flow watchdog samples + bounces (a structural subset of import('@freemixer/audio-engine').SoftwareMixer so tests inject a fake).