propagate_merged_cells used an overlap-based predicate with ±tol
slop that returned true at shared row boundaries — a rect whose
top exactly equals row N's bottom lies entirely below the row, yet
the predicate considered it to span row N. When multiple background
rects aligned on a shared Y edge (e.g. consecutive row-stripe
shading), each adjacent rect would over-reach by one row, cascading
labels and data from unrelated rows into a single merged cell.
Replace the overlap predicate with a containment check: rect bottom
at or below row bottom, rect top at or above row top (each within
tol). Genuine merged-cell rects fully contain the rows they span;
tangent rects do not.
Update two snapshots that were encoding the old buggy output.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
