Collapse the per-(kind, reason) suppression rows into one entry per
reason, with each kind preserved as a segment. The reason list is
sorted by total count descending so the highest-impact row comes
first; segments within a reason are sorted by kind for stable colour
ordering across renders.
Collapse the per-(kind, reason) suppression rows into one entry per reason, with each kind preserved as a segment. The reason list is sorted by total count descending so the highest-impact row comes first; segments within a reason are sorted by kind for stable colour ordering across renders.