Merge PR #564

# Conflicts:
#	README.md
#	crates/ui-egui/src/i18n.rs
#	docs/localization.md
#	docs/parity.md

docs/localization.md

@@ -29,14 +29,17 @@ are in [`localization-zh-hans.md`](localization-zh-hans.md), [`localization-zh-h
        PtBr, "pt-br", "Português (Brasil)", "Latn", include_str!("../locales/pt-br.json");
        De, "de", "Deutsch", "Latn", include_str!("../locales/de.json");
        Ru, "ru", "Русский", "Cyrl", include_str!("../locales/ru.json");
+       Uk, "uk", "Українська", "Cyrl", include_str!("../locales/uk.json");
    }
    ```
 
    The fields are the BCP-47 code (also the settings-file value), the **endonym** shown in the
    Language menu, the ISO 15924 script (`Latn`, `Jpan`, `Hans`, `Hant`, `Kore`…), and the embedded
    catalog. `build.rs` picks up `<code>-formats.json` by name, so the macro and the format lookup
-   follow automatically — nothing else in the UI needs to change. The menus, the settings row, the
-   keyboard-shortcut sheet and the control channel all read the table.
+   follow automatically. Add the corresponding `app.language.<name>` entry to
+   `LANGUAGE_COMMANDS` and `language_from_command` in `src/menus.rs`, and to the
+   `language_commands_cover_every_language` test. Settings read the locale table; menus and
+   the control channel share the language-command mapping.
 3. **Make sure the glyphs exist.** The script drives which craft-fonts faces the UI installs: a
    language whose script has no face in the build shows boxes (the test says so instead of failing).
    Fonts live in [storytold/craft-fonts](https://github.com/storytold/craft-fonts), never here; a