Lua 5.0 (Vanilla 1.12) has no % operator outside string formatting; it is a
parse error. Route the 9 arithmetic modulo sites through the existing math.mod
shim (Compat/Compat.lua) so the addon parses on 5.0 through Retail.
Sites: QuestieDB daily/weekly flag tests, QuestieEvent DMF cycle math,
QuestieLearner GUID/flag math, QuestiePlayer race/class flag tests.