Supersedes71221837. Samples every t* 0.5 (interval-mean forces), trailing t* 50..60 window (21 samples); range <= 10 % and |slope*window| <= 2 % of each official band width. Verdict on the window mean with the distance to the nearest band edge. Our engineering rule, frozen before any run. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> (cherry picked from commit869d60d78e)