- curt_subtract_avg (+ -SUBAVG filename tag): subtract the input per-pixel temporal
  mean before LoG. Removes the static treeline edge (and so its 8px tile-grid
  horizontal streak and the first-LReLU amplification of it); the moving target is
  not in the average, so it survives. Uses the whole sequence (not realtime; realtime
  would use a prior-run average).
- DNN compute-window: the timing ROI (curt_time_from/to) now gates the DNN inference
  loop (only in-window scenes are inferred), not just the saved output - fast iteration
  on a target's few seconds.
- DNN -> recurrent layer: feed the DNN field to runRecurrentLevel (per selected level,
  curt_recur_*). curt_dnn_recur_splat toggles feed-as-is vs bilinear splat of each
  pixel's velocity vector to its fractional (px+dx,py+dy) so neighbours reinforce in one
  sub-pixel bin (-SPLAT mark). curt_dnn_recur_scale (default 10) lifts the [0,1] field
  (peaks ~0.1) to the recurrent's tuned rs_min~1.0 scale. splatField() helper added.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>