6 comparison clips, played at 10fps (real playback). Layout per frame:
ORIGINAL (held) | SLOWED 3x -- head row on top, wrist row below.
The red PICK banner marks the F_z-detected pick window (+/-0.5s), slowed 3x.
When the right column moves smoothly while the left pauses, that span is the slowed window.
Detected picks: ep0@36 ep50@23 ep100@24 ep150@26 ep200@31 ep250@37 (frames).
