Czech counts take three integer forms: one (1), few (2-4) and other
(0 and 5+). Since #257 catalogs can supply `few`, so `plural()` gets a
Czech rule and the 38 plural entries in cs.toml now read naturally
("1 vrstva", "3 vrstvy", "5 vrstev") instead of the count-neutral
"Vrstvy: {n}" that #469 used for everything but 1.
Test czech_integer_plurals covers the rule (1; 2-4; 0, 5, 11, 12, 21,
22, 100, 1 000 000), a real key through counted(), and that every Czech
plural entry has one and few. Docs no longer say Czech has only one/other.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Adds crates/ui-egui/locales/cs.toml with all 2165 entries (ui, commands,
menu), marked "draft — needs native review" and kept out of COMPLETE.
Plurals use one/other only; the other form is worded count-neutral so it
reads correctly for 2-4 as well. Lists cs in the pref.language help text,
adds a cs_CZ.UTF-8 detection test and updates the localization docs.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
