main split Czech's suggest_in into one helper per round for the
cognitive_complexity limit (storytold/wordcraft#4501). On this branch that code is the
shared affix_suggest::suggest_in (36 of 30), so cs/suggest.rs stays the
thin wrapper and the shared function gets the same split. The candidates
are offered in the same order; a dump of 13,081 calls over every
language's test dictionary matches the old engine except one: the typo
round counts the lower-cased letters, so "İ" (two letters lower case)
now gets "I" in Polish, where the old count stopped one letter short.