redbear-ecmd: scheme loop replaces stdout on Redox
(/scheme/net/usbECM_<N>), notification reader kept for
CDC link state / speed change events on both paths.
redbear-usbaudiod: scheme loop replaces stdout on Redox
(/scheme/audio/usbAudio_<N>), stdin→isoch_OUT playback
thread kept for host stdout path only.
All 4 class drivers now fully wired:
acmd → scheme event loop active on Redox ✅
ftdi → scheme event loop active on Redox ✅
ecmd → scheme event loop active on Redox ✅
usbaudiod → scheme event loop active on Redox ✅
vasilito
5b4f2ac984