Adds one log line per AdjustOffset call (gated by ACDREAM_PROBE_STEP_WALK)
naming the branch taken (no-cp / no-cp-slide / slide-degenerate /
slide-crease / into-plane / away-plane, optionally +safety-push) plus
zGain = output.Z - input.Z.
No math or control-flow changes — pure observability so the next capture
can disambiguate the three failure-mode hypotheses for the cellar-ramp
climb cap. Re-reading the existing capture (a6-issue98-negpoly-...log)
showed the sphere DOES climb 90.00 -> 92.79 (2.79 m gain), then caps,
contradicting the divergence comparison's "no altitude gain" framing.
The real question is what stops the climb at world Z ~= 92.79 with the
cottage floor still 1.21 m higher. Existing [step-walk] probes wrap
AdjustOffset; this new probe reveals which branch the projection takes.
Fix plan with the four-branch decision tree at
docs/superpowers/plans/2026-05-23-a6-p3-issue98-cellar-up-fix.md.
Test baseline maintained: 1167 + 8.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>