Mouth lead: nudge performance tracks ahead of the clock

Smoothing does not literally delay anything - a centred moving average has zero
phase lag - but it blurs onsets, so the visually salient moment of a mouth
opening moves later even though the mean does not. Animators also draw mouth
shapes a frame or two ahead of the sound as standard practice, so this is the
normal control rather than a workaround.

Only the performance tracks shift; the head and audio stay put, since it is the
mouth that should anticipate. In photo-underlay modes the vector mouth will
therefore no longer match the frame behind it, which is expected.

The lead is baked into the exported take - key f carries the pose from source
frame f+lead - so the Animator Pro renderer never needs to know about it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

manifest.json

@@ -1 +1 @@
-{"fps":12,"frames":37,"dir":"frames","audio":"audio.wav","source":"IMG_8486.MOV"}
+{"fps":24,"frames":74,"dir":"frames","audio":"audio.wav","source":"IMG_8486.MOV"}