Add Korean UI localization (#2895)

* Add Korean UI localization

Refreshes the Korean translation from #1544 against the current client locale surface and adds cross-platform locale detection coverage.\n\nCo-authored-by: JinHyeok Jeong <150323322+Kesta-bos@users.noreply.github.com>

* fix(i18n): preserve reviewed Korean status labels

Restore the wording corrections contributed in the original Korean localization work and lock them with exact-copy assertions.

Co-authored-by: JinHyeok Jeong <150323322+Kesta-bos@users.noreply.github.com>

---------

Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>
Co-authored-by: JinHyeok Jeong <150323322+Kesta-bos@users.noreply.github.com>

docs/i18n.md

@@ -9,11 +9,12 @@ Paseo client UI translations live in `packages/app/src/i18n`.
 - `es`
 - `fr`
 - `ja`
+- `ko`
 - `pt-BR`
 - `ru`
 - `zh-CN`
 
-The persisted app language setting is `"system" | "ar" | "en" | "es" | "fr" | "ja" | "pt-BR" | "ru" | "zh-CN"`. `"system"` follows the device or browser locale when it maps to a supported locale; unsupported system locales fall back to English. Japanese maps from system locales `ja` and Japanese regional locales. Brazilian Portuguese maps from system locales `pt-BR` and bare `pt`; other Portuguese regional locales remain unsupported until explicitly added.
+The persisted app language setting is `"system" | "ar" | "en" | "es" | "fr" | "ja" | "ko" | "pt-BR" | "ru" | "zh-CN"`. `"system"` follows the device or browser locale when it maps to a supported locale; unsupported system locales fall back to English. Japanese maps from system locales `ja` and Japanese regional locales. Korean maps from system locales `ko` and Korean regional locales. Brazilian Portuguese maps from system locales `pt-BR` and bare `pt`; other Portuguese regional locales remain unsupported until explicitly added.
 
 ## Translation Scope
 
@@ -23,7 +24,7 @@ Do not translate agent output, daemon output, terminal contents, file paths, pro
 
 ## Adding Copy
 
-English source strings live in `packages/app/src/i18n/resources/en.ts`. Simplified Chinese strings live in `packages/app/src/i18n/resources/zh-CN.ts`.
+English source strings live in `packages/app/src/i18n/resources/en.ts`. Each supported locale has a matching resource in `packages/app/src/i18n/resources`.
 
 For migrated screens and components, use `useTranslation()` and pass translated text into UI primitives. Low-level primitives such as `<Button>` do not import translation state unless they own the text they render.
 
@@ -89,3 +90,4 @@ Within a migrated surface, do not leave mixed-language neighboring labels when t
 - Batch 4Y tightened the translation boundary so React components and custom hooks use `useTranslation()` while pure helpers keep direct `i18n.t(...)` fallbacks, and migrated remaining small UI/accessibility fallbacks across message details, menu backdrops, startup errors, sidebar PR badges, settings/project accessibility labels, composer send/create/download fallbacks, client slash-command descriptions, terminal subscribe errors, and desktop update completion text. Provider catalog metadata, shortcut registry fallbacks, agent/daemon/protocol reasons, terminal contents, raw runtime errors, and user/project/workspace names remain untranslated.
 - Batch 4Z expanded the supported locale set to the six UN official languages: Arabic, Chinese, English, French, Russian, and Spanish. Arabic, French, Russian, and Spanish now have full client-owned UI resource coverage, with key parity, fallback-ratio, and interpolation-placeholder tests guarding the generated translations. Arabic does not enable RTL layout direction in this batch.
 - Batch 5A added Brazilian Portuguese (`pt-BR`) resource coverage, language selector labels, i18next registration, and system-locale mapping for `pt-BR` and bare `pt`. Non-Brazilian Portuguese regional locales remain unsupported until a matching resource is added.
+- Batch 5B added Korean (`ko`) resource coverage, language selector labels, i18next registration, and system-locale mapping for `ko` and Korean regional locales.

packages/app/e2e/browser/settings-i18n.spec.ts

@@ -21,3 +21,21 @@ test("Settings language selector switches General labels", async ({ page }) => {
 
   await expect(page.getByText("Default send", { exact: true }).first()).toBeVisible();
 });
+
+test("Settings language selector switches to Korean", async ({ page }) => {
+  test.setTimeout(120_000);
+
+  await gotoAppShell(page);
+  await openSettings(page);
+  await openSettingsSection(page, "general");
+
+  await page.getByRole("button", { name: "System", exact: true }).click();
+  await page.getByRole("button", { name: "한국어 - Korean", exact: true }).click();
+
+  await expect(page.getByText("기본 전송", { exact: true }).first()).toBeVisible();
+
+  await page.getByRole("button", { name: "한국어", exact: true }).click();
+  await page.getByRole("button", { name: "English - 영어", exact: true }).click();
+
+  await expect(page.getByText("Default send", { exact: true }).first()).toBeVisible();
+});

packages/app/src/i18n/i18next.ts

@@ -6,6 +6,7 @@ import { en } from "./resources/en";
 import { es } from "./resources/es";
 import { fr } from "./resources/fr";
 import { ja } from "./resources/ja";
+import { ko } from "./resources/ko";
 import { ptBR } from "./resources/pt-BR";
 import { ru } from "./resources/ru";
 import { zhCN } from "./resources/zh-CN";
@@ -23,6 +24,7 @@ observeI18nInit(
       es: { translation: es },
       fr: { translation: fr },
       ja: { translation: ja },
+      ko: { translation: ko },
       "pt-BR": { translation: ptBR },
       ru: { translation: ru },
       "zh-CN": { translation: zhCN },

packages/app/src/i18n/locales.test.ts

@@ -9,8 +9,8 @@ import {
 describe("parseAppLanguage", () => {
   it("accepts system and all supported language locales", () => {
     expect(
-      ["system", "ar", "en", "es", "fr", "ja", "pt-BR", "ru", "zh-CN"].map(parseAppLanguage),
+      ["system", "ar", "en", "es", "fr", "ja", "ko", "pt-BR", "ru", "zh-CN"].map(parseAppLanguage),
-    ).toEqual(["system", "ar", "en", "es", "fr", "ja", "pt-BR", "ru", "zh-CN"]);
+    ).toEqual(["system", "ar", "en", "es", "fr", "ja", "ko", "pt-BR", "ru", "zh-CN"]);
   });
 
   it("returns null for unknown values", () => {
@@ -26,6 +26,7 @@ describe("parseAppLanguage", () => {
       "es",
       "fr",
       "ja",
+      "ko",
       "pt-BR",
       "ru",
       "zh-CN",
@@ -37,6 +38,7 @@ describe("formatLanguageOptionLabel", () => {
   it("shows the native language name and English name in English UI", () => {
     const arabic = LANGUAGE_OPTIONS.find((option) => option.value === "ar");
     const japanese = LANGUAGE_OPTIONS.find((option) => option.value === "ja");
+    const korean = LANGUAGE_OPTIONS.find((option) => option.value === "ko");
     const portuguese = LANGUAGE_OPTIONS.find((option) => option.value === "pt-BR");
     const spanish = LANGUAGE_OPTIONS.find((option) => option.value === "es");
     const chinese = LANGUAGE_OPTIONS.find((option) => option.value === "zh-CN");
@@ -44,12 +46,14 @@ describe("formatLanguageOptionLabel", () => {
     expect([
       formatLanguageOptionLabel(arabic!, "en", "System"),
       formatLanguageOptionLabel(japanese!, "en", "System"),
+      formatLanguageOptionLabel(korean!, "en", "System"),
       formatLanguageOptionLabel(portuguese!, "en", "System"),
       formatLanguageOptionLabel(spanish!, "en", "System"),
       formatLanguageOptionLabel(chinese!, "en", "System"),
     ]).toEqual([
       "العربية - Arabic",
       "日本語 - Japanese",
+      "한국어 - Korean",
       "Português brasileiro - Brazilian Portuguese",
       "Español - Spanish",
       "简体中文 - Simplified Chinese",
@@ -71,10 +75,12 @@ describe("formatLanguageOptionLabel", () => {
   it("uses a single label when both language names match", () => {
     const english = LANGUAGE_OPTIONS.find((option) => option.value === "en");
     const japanese = LANGUAGE_OPTIONS.find((option) => option.value === "ja");
+    const korean = LANGUAGE_OPTIONS.find((option) => option.value === "ko");
     const portuguese = LANGUAGE_OPTIONS.find((option) => option.value === "pt-BR");
 
     expect(formatLanguageOptionLabel(english!, "en", "System")).toBe("English");
     expect(formatLanguageOptionLabel(japanese!, "ja", "システム")).toBe("日本語");
+    expect(formatLanguageOptionLabel(korean!, "ko", "시스템")).toBe("한국어");
     expect(formatLanguageOptionLabel(portuguese!, "pt-BR", "Sistema")).toBe("Português brasileiro");
   });
 
@@ -92,6 +98,7 @@ describe("resolveSupportedLocale", () => {
     expect(resolveSupportedLocale("es", ["en-US"])).toBe("es");
     expect(resolveSupportedLocale("fr", ["en-US"])).toBe("fr");
     expect(resolveSupportedLocale("ja", ["en-US"])).toBe("ja");
+    expect(resolveSupportedLocale("ko", ["en-US"])).toBe("ko");
     expect(resolveSupportedLocale("pt-BR", ["en-US"])).toBe("pt-BR");
     expect(resolveSupportedLocale("ru", ["en-US"])).toBe("ru");
     expect(resolveSupportedLocale("zh-CN", ["en-US"])).toBe("zh-CN");
@@ -103,11 +110,18 @@ describe("resolveSupportedLocale", () => {
     expect(resolveSupportedLocale("system", ["es-MX"])).toBe("es");
     expect(resolveSupportedLocale("system", ["fr-CA"])).toBe("fr");
     expect(resolveSupportedLocale("system", ["ja-JP"])).toBe("ja");
+    expect(resolveSupportedLocale("system", ["ko-KR"])).toBe("ko");
     expect(resolveSupportedLocale("system", ["pt-BR"])).toBe("pt-BR");
     expect(resolveSupportedLocale("system", ["pt"])).toBe("pt-BR");
     expect(resolveSupportedLocale("system", ["ru-RU"])).toBe("ru");
   });
 
+  it("maps Korean system locales to Korean", () => {
+    expect(resolveSupportedLocale("system", ["ko"])).toBe("ko");
+    expect(resolveSupportedLocale("system", ["ko-KR"])).toBe("ko");
+    expect(resolveSupportedLocale("system", ["ko-KP"])).toBe("ko");
+  });
+
   it("does not map non-Brazilian Portuguese system locales to Brazilian Portuguese", () => {
     expect(resolveSupportedLocale("system", ["pt-PT"])).toBe("en");
     expect(resolveSupportedLocale("system", ["pt-AO"])).toBe("en");

packages/app/src/i18n/locales.ts

@@ -1,4 +1,4 @@
-export type SupportedLocale = "ar" | "en" | "es" | "fr" | "ja" | "pt-BR" | "ru" | "zh-CN";
+export type SupportedLocale = "ar" | "en" | "es" | "fr" | "ja" | "ko" | "pt-BR" | "ru" | "zh-CN";
 export type AppLanguage = "system" | SupportedLocale;
 
 export interface LanguageOption {
@@ -15,6 +15,7 @@ export const LANGUAGE_OPTIONS: LanguageOption[] = [
   { value: "es", labelKey: "settings.general.language.options.es" },
   { value: "fr", labelKey: "settings.general.language.options.fr" },
   { value: "ja", labelKey: "settings.general.language.options.ja" },
+  { value: "ko", labelKey: "settings.general.language.options.ko" },
   { value: "pt-BR", labelKey: "settings.general.language.options.ptBR" },
   { value: "ru", labelKey: "settings.general.language.options.ru" },
   { value: "zh-CN", labelKey: "settings.general.language.options.zhCN" },
@@ -27,6 +28,7 @@ const SUPPORTED_LANGUAGES = new Set<AppLanguage>([
   "es",
   "fr",
   "ja",
+  "ko",
   "pt-BR",
   "ru",
   "zh-CN",
@@ -37,6 +39,7 @@ const LANGUAGE_NATIVE_NAMES: Record<SupportedLocale, string> = {
   es: "Español",
   fr: "Français",
   ja: "日本語",
+  ko: "한국어",
   "pt-BR": "Português brasileiro",
   ru: "Русский",
   "zh-CN": "简体中文",
@@ -48,6 +51,7 @@ const LANGUAGE_NAMES_BY_LOCALE: Record<SupportedLocale, Record<SupportedLocale,
     es: "الإسبانية",
     fr: "الفرنسية",
     ja: "اليابانية",
+    ko: "الكورية",
     "pt-BR": "البرتغالية البرازيلية",
     ru: "الروسية",
     "zh-CN": "الصينية المبسطة",
@@ -58,6 +62,7 @@ const LANGUAGE_NAMES_BY_LOCALE: Record<SupportedLocale, Record<SupportedLocale,
     es: "Spanish",
     fr: "French",
     ja: "Japanese",
+    ko: "Korean",
     "pt-BR": "Brazilian Portuguese",
     ru: "Russian",
     "zh-CN": "Simplified Chinese",
@@ -68,6 +73,7 @@ const LANGUAGE_NAMES_BY_LOCALE: Record<SupportedLocale, Record<SupportedLocale,
     es: "español",
     fr: "francés",
     ja: "japonés",
+    ko: "coreano",
     "pt-BR": "portugués brasileño",
     ru: "ruso",
     "zh-CN": "chino simplificado",
@@ -78,6 +84,7 @@ const LANGUAGE_NAMES_BY_LOCALE: Record<SupportedLocale, Record<SupportedLocale,
     es: "espagnol",
     fr: "français",
     ja: "japonais",
+    ko: "coréen",
     "pt-BR": "portugais brésilien",
     ru: "russe",
     "zh-CN": "chinois simplifié",
@@ -88,16 +95,29 @@ const LANGUAGE_NAMES_BY_LOCALE: Record<SupportedLocale, Record<SupportedLocale,
     es: "スペイン語",
     fr: "フランス語",
     ja: "日本語",
+    ko: "韓国語",
     "pt-BR": "ブラジルポルトガル語",
     ru: "ロシア語",
     "zh-CN": "簡体字中国語",
   },
+  ko: {
+    ar: "아랍어",
+    en: "영어",
+    es: "스페인어",
+    fr: "프랑스어",
+    ja: "일본어",
+    ko: "한국어",
+    "pt-BR": "브라질 포르투갈어",
+    ru: "러시아어",
+    "zh-CN": "중국어 간체",
+  },
   "pt-BR": {
     ar: "árabe",
     en: "inglês",
     es: "espanhol",
     fr: "francês",
     ja: "japonês",
+    ko: "coreano",
     "pt-BR": "Português brasileiro",
     ru: "russo",
     "zh-CN": "chinês simplificado",
@@ -108,6 +128,7 @@ const LANGUAGE_NAMES_BY_LOCALE: Record<SupportedLocale, Record<SupportedLocale,
     es: "испанский",
     fr: "французский",
     ja: "японский",
+    ko: "корейский",
     "pt-BR": "бразильский португальский",
     ru: "русский",
     "zh-CN": "упрощенный китайский",
@@ -118,12 +139,23 @@ const LANGUAGE_NAMES_BY_LOCALE: Record<SupportedLocale, Record<SupportedLocale,
     es: "西班牙语",
     fr: "法语",
     ja: "日语",
+    ko: "韩语",
     "pt-BR": "巴西葡萄牙语",
     ru: "俄语",
     "zh-CN": "简体中文",
   },
 };
 
+const REGIONAL_LANGUAGE_LOCALES: Readonly<Record<string, SupportedLocale>> = {
+  ar: "ar",
+  en: "en",
+  es: "es",
+  fr: "fr",
+  ja: "ja",
+  ko: "ko",
+  ru: "ru",
+};
+
 export function parseAppLanguage(value: unknown): AppLanguage | null {
   return typeof value === "string" && SUPPORTED_LANGUAGES.has(value as AppLanguage)
     ? (value as AppLanguage)
@@ -158,27 +190,14 @@ export function resolveSupportedLocale(
 
   for (const locale of systemLocales) {
     const normalized = locale.toLowerCase();
-    if (normalized === "ar" || normalized.startsWith("ar-")) {
+    const baseLanguage = normalized.split("-", 1)[0];
-      return "ar";
+    const regionalLocale = REGIONAL_LANGUAGE_LOCALES[baseLanguage];
-    }
+    if (regionalLocale) {
-    if (normalized === "en" || normalized.startsWith("en-")) {
+      return regionalLocale;
-      return "en";
-    }
-    if (normalized === "es" || normalized.startsWith("es-")) {
-      return "es";
-    }
-    if (normalized === "fr" || normalized.startsWith("fr-")) {
-      return "fr";
-    }
-    if (normalized === "ja" || normalized.startsWith("ja-")) {
-      return "ja";
     }
     if (normalized === "pt" || normalized === "pt-br") {
       return "pt-BR";
     }
-    if (normalized === "ru" || normalized.startsWith("ru-")) {
-      return "ru";
-    }
     if (normalized === "zh" || normalized === "zh-cn" || normalized.startsWith("zh-hans")) {
       return "zh-CN";
     }

packages/app/src/i18n/resources.test.ts

@@ -6,6 +6,7 @@ import { en } from "./resources/en";
 import { es } from "./resources/es";
 import { fr } from "./resources/fr";
 import { ja } from "./resources/ja";
+import { ko } from "./resources/ko";
 import { ptBR } from "./resources/pt-BR";
 import { ru } from "./resources/ru";
 import { zhCN } from "./resources/zh-CN";
@@ -109,6 +110,7 @@ describe("translation resources", () => {
     expect(flattenKeys(es).sort()).toEqual(englishKeys);
     expect(flattenKeys(fr).sort()).toEqual(englishKeys);
     expect(flattenKeys(ja).sort()).toEqual(englishKeys);
+    expect(flattenKeys(ko).sort()).toEqual(englishKeys);
     expect(flattenKeys(ptBR).sort()).toEqual(englishKeys);
     expect(flattenKeys(ru).sort()).toEqual(englishKeys);
     expect(flattenKeys(zhCN).sort()).toEqual(englishKeys);
@@ -121,6 +123,7 @@ describe("translation resources", () => {
     expect(countMatchingEnglishStrings(es)).toBeLessThan(maxFallbackStrings);
     expect(countMatchingEnglishStrings(fr)).toBeLessThan(maxFallbackStrings);
     expect(countMatchingEnglishStrings(ja)).toBeLessThan(maxFallbackStrings);
+    expect(countMatchingEnglishStrings(ko)).toBeLessThan(maxFallbackStrings);
     expect(countMatchingEnglishStrings(ptBR)).toBeLessThan(maxFallbackStrings);
     expect(countMatchingEnglishStrings(ru)).toBeLessThan(maxFallbackStrings);
     expect(countMatchingEnglishStrings(zhCN)).toBeLessThan(maxFallbackStrings);
@@ -131,6 +134,7 @@ describe("translation resources", () => {
     expect(findInterpolationMismatches(es)).toEqual([]);
     expect(findInterpolationMismatches(fr)).toEqual([]);
     expect(findInterpolationMismatches(ja)).toEqual([]);
+    expect(findInterpolationMismatches(ko)).toEqual([]);
     expect(findInterpolationMismatches(ptBR)).toEqual([]);
     expect(findInterpolationMismatches(ru)).toEqual([]);
     expect(findInterpolationMismatches(zhCN)).toEqual([]);
@@ -147,6 +151,7 @@ describe("translation resources", () => {
     expect(es.modelSelector.modelCountPlural).toBe("{{count}} modelos");
     expect(fr.modelSelector.modelCountPlural).toBe("{{count}} modèles");
     expect(ja.modelSelector.modelCountPlural).toBe("{{count}}つのモデル");
+    expect(ko.modelSelector.modelCountPlural).toBe("모델 {{count}}개");
     expect(ptBR.modelSelector.modelCountPlural).toBe("{{count}} modelos");
     expect(ru.modelSelector.modelCountPlural).toBe("{{count}} моделей");
     expect(zhCN.modelSelector.modelCountPlural).toBe("{{count}} 个模型");
@@ -159,6 +164,11 @@ describe("translation resources", () => {
     expect(zhCN.settings.providers.models.many).toBe("{{count}} 个 Model");
   });
 
+  it("preserves reviewed Korean status labels", () => {
+    expect(ko.common.states.starting).toBe("시작 중...");
+    expect(ko.desktop.daemon.status.notRunning).toBe("실행 중이 아님");
+  });
+
   it("labels the immediate add-to-chat action without an ellipsis", () => {
     expect(en.workspace.fileActions.addToChat).toBe("Add to chat");
   });

packages/app/src/i18n/resources/ar.ts

@@ -1750,6 +1750,7 @@ export const ar: TranslationResources = {
           es: "Español",
           fr: "Français",
           ja: "日本語",
+          ko: "한국어",
           ptBR: "Português brasileiro",
           ru: "Русский",
           zhCN: "中文",

packages/app/src/i18n/resources/en.ts

@@ -1760,6 +1760,7 @@ export const en = {
           es: "Spanish",
           fr: "French",
           ja: "Japanese",
+          ko: "Korean",
           ptBR: "Brazilian Portuguese",
           ru: "Russian",
           zhCN: "Simplified Chinese",

packages/app/src/i18n/resources/es.ts

@@ -1797,6 +1797,7 @@ export const es: TranslationResources = {
           es: "Español",
           fr: "Français",
           ja: "日本語",
+          ko: "한국어",
           ptBR: "Português brasileiro",
           ru: "Русский",
           zhCN: "中文",

packages/app/src/i18n/resources/fr.ts

@@ -1799,6 +1799,7 @@ export const fr: TranslationResources = {
           es: "Español",
           fr: "Français",
           ja: "日本語",
+          ko: "한국어",
           ptBR: "Português brasileiro",
           ru: "Русский",
           zhCN: "中文",

packages/app/src/i18n/resources/ja.ts

@@ -1765,6 +1765,7 @@ export const ja: TranslationResources = {
           es: "スペイン語",
           fr: "フランス語",
           ja: "日本語",
+          ko: "韓国語",
           ptBR: "ブラジルポルトガル語",
           ru: "ロシア語",
           zhCN: "簡体字中国語",

packages/app/src/i18n/resources/pt-BR.ts

@@ -1781,6 +1781,7 @@ export const ptBR: TranslationResources = {
           es: "Espanhol",
           fr: "Francês",
           ja: "Japonês",
+          ko: "Coreano",
           ptBR: "Português brasileiro",
           ru: "Russo",
           zhCN: "Chinês simplificado",

packages/app/src/i18n/resources/ru.ts

@@ -1785,6 +1785,7 @@ export const ru: TranslationResources = {
           es: "Español",
           fr: "Français",
           ja: "日本語",
+          ko: "한국어",
           ptBR: "Português brasileiro",
           ru: "Русский",
           zhCN: "中文",

packages/app/src/i18n/resources/zh-CN.ts

@@ -1729,6 +1729,7 @@ export const zhCN: TranslationResources = {
           es: "Español",
           fr: "Français",
           ja: "日本語",
+          ko: "한국어",
           ptBR: "Português brasileiro",
           ru: "Русский",
           zhCN: "简体中文",