Split language from region: omarchy-language and Setup > Language own LANG

omarchy-region and install/config/region.sh no longer touch the locale;
both logout prompts are worded through omarchy-text.

test/shell.d/menu-test.sh

@@ -305,6 +305,15 @@ assert(
     && defaultById['setup.region.china'].action.includes('omarchy-region cn'),
   'menu offers Global and China under Setup > Region'
 )
+const languageEntries = defaultItems.filter(item => item.parent === 'setup.language')
+assert(
+  languageEntries.map(item => item.id).join('\0') === 'setup.language.en\0setup.language.zh'
+    && defaultById['setup.language.en'].checked.includes('== \"en_US.UTF-8\"')
+    && defaultById['setup.language.zh'].checked.includes('== \"zh_CN.UTF-8\"')
+    && defaultById['setup.language.en'].action.includes('omarchy-language en')
+    && defaultById['setup.language.zh'].action.includes('omarchy-language zh'),
+  'menu offers English and Simplified Chinese under Setup > Language'
+)
 // Software you already have keeps its place in Install, dimmed rather than
 // dropped, so the list reads as a catalog of what Omarchy can install.
 // Chromium Account is the sole Install row with anything left to hide for, so