The absence mapping was asserted for two of the ten dense tracks. Each block
hands `pack` an :absent predicate that derives a feature from a track INDEX, so
the predicate and the vector literal beside it agree only by hand, in four
places — and three of the four blocks had nothing checking them.
Give each feature a DIFFERENT gap window, so a track wired to the wrong feature
shows up as absence inside somebody else's window. A single shared window passes
under any permutation, which is the failure port-plan mechanical fact #2 warns
about: swap left for right and every part is still roughly where it belongs, so
it survives inspection.
Verified by mutation, since a test that cannot fail is worth nothing. Swapping
the brow block's two tracks, and swapping eye-block tracks 1 and 3 while leaving
0 and 2 correct, both now fail loudly; neither was caught before.
Also pin the teeth. They are their own feature so they can carry their own
:area :teeth parameters, which means an occluded mouth sets no bit on them; they
are dropped regardless because they stencil on :mouth-in and scene/finish drops a
node whose stencil drew nothing. Both frames come from an unannotated reference
clip, because the interior only draws on an open mouth and a frame the mouth was
shut on would have passed for the wrong reason.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B87NVmiU36qQmN9gmFYnJ9
b6517f837a