The deltacast bridge captures audio (DISJOINED_ANC VHD stream -> FIFO) and
video (VHD stream -> framecache ring -> fc_pipe -> ffmpeg) on separate paths
with independent buffering. The video path is buffered deeper, so audio reaches
the muxer AHEAD of its matching video frame (user-confirmed: audio ahead of
video on lip-sync). --audio-delay-ms / FC_AUDIO_DELAY_MS prepends N ms of real
PCM silence to the audio stream once per reader-attach, shifting the audio
timeline N ms later to re-align. One value, all 8 ports, drift-free (ffmpeg
derives audio PTS from sample count). Default 0 = unchanged (non-destructive).
Operator tunes once against a lip-sync reference. Also fixes promotion worker
to reset orphaned processing assets on failure (was stuck forever).
feeab99a36