Records ||f_i(x_i)|| / ||x_i|| on video rows for every block, averaged
over each run's steps, and pairs the profile with that run's rating.
Answers the question that gates rating-driven block weighting: is H3's
depth profile flat (nothing to aim at) or structured? Reports a
scale-invariant flatness number, and once a key has 2+ liked and 2+
disliked runs, which blocks run hotter on the liked ones.
Steers nothing. Installed BEFORE any steering hook so the delta it
records is the block's own, not one already containing an injection.
Bounded cost: two norms per block per step on ~512 strided rows, no
extra forward pass, results accumulated as device tensors and synced
once per run rather than 50x per step. Says so explicitly when it
records nothing, since an empty capture and a flat profile are
otherwise indistinguishable downstream.
Adjacent to per-block residual steering, removed in b7ed4f9 for
finding no rating signal above the 4th decimal -- that pass had no
per-step resolution, which its own removal note named as the gap.
This either reproduces that null definitively or it doesn't.
digital-garbage
d6981036d0