test(i18n): cover language preference persistence

scripts/validate.mjs

@@ -72,10 +72,25 @@ assert.equal(localeContext.LifeI18n.language(), "zh", "cloud settings cannot ove
 localeContext.setLanguage("en");
 assert.equal(localeContext.LifeI18n.language(), "en", "manual English choice overrides browser language");
 assert.equal(localeContext.LifeI18n.t("app.today"), "TODAY");
+const reloadedManualContext = vm.createContext({
+  navigator: { languages: ["en-US"] }, localStorage: makeStorage(),
+  LifeOSLocales: { en: assets.localeEn, "zh-CN": assets.localeZh },
+});
+reloadedManualContext.window = reloadedManualContext;
+vm.runInContext(assets.i18nJs, reloadedManualContext);
+assert.equal(reloadedManualContext.LifeI18n.language(), "en", "a reloaded page starts in automatic mode when no manual choice was saved");
 localeContext.navigator.languages = ["zh-CN"];
 localeContext.setLanguage("auto");
 assert.equal(localeContext.LifeI18n.preference(), "auto");
 assert.equal(localeContext.LifeI18n.language(), "zh", "auto mode ignores stale cloud preference and follows this device");
+localeContext.setLanguage("en");
+const persistedManualContext = vm.createContext({
+  navigator: { languages: ["zh-CN"] }, localStorage,
+  LifeOSLocales: { en: assets.localeEn, "zh-CN": assets.localeZh },
+});
+persistedManualContext.window = persistedManualContext;
+vm.runInContext(assets.i18nJs, persistedManualContext);
+assert.equal(persistedManualContext.LifeI18n.language(), "en", "a manually selected language persists across reloads");
 const migratedStorage = makeStorage({ lifeos_settings: JSON.stringify({ language: "zh" }) });
 const migratedContext = vm.createContext({
   navigator: { languages: ["en-US"] }, localStorage: migratedStorage,