i18n(cs): Quit DesignCraft

Czech for the app-menu entry added on main since this PR was opened.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/i18n/cs.rs

@@ -398,6 +398,7 @@ pub(super) const TABLE: &[(&str, &str)] = &[
     ("Spreads of up to 10 pages", "Dvoustrany až o 10 stránkách"),
     ("for", "na"),
     ("About DesignCraft", "O aplikaci DesignCraft"),
+    ("Quit DesignCraft", "Ukončit DesignCraft"),
     ("Accept All Changes", "Přijmout všechny změny"),
     ("Activate Document", "Aktivovat dokument"),
     ("Add Anchor Point", "Přidat kotevní bod"),