An icon-set rule without stored thresholds (every rule made by
home.conditionalFormat, and the sales sample) was written as an empty
<iconSet>, which CT_IconSet forbids (cfvo minOccurs 2); openpyxl drops it.
The writer now always emits one cfvo per icon: the stored thresholds when
there is one per icon, the lower bound prepended when it is missing, else
Excel's defaults (percent 0/33/67, 0/25/50/75, 0/20/40/60/80).
Evaluation read the thresholds as one fewer than the icons, but files
carry one per icon (the first is the lower bound), so thresholds read from
a file were ignored. Both now share icon_count and default_icon_thresholds
in gridcraft-model; icon_count is clamped to 3..=5 so a set name like
"0Foo" can't underflow k - 1.
generated with Claude Code
32d0a866f9