feat: add Korean (한국어) localization

Add Korean language support with full UI translations including
menu items, update messages, and time format suffixes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/localization/korean.rs

@@ -0,0 +1,37 @@
+use super::Strings;
+
+pub(super) const UPDATE_VIA_WINGET_LABEL: &str = "WinGet으로 업데이트";
+
+pub(super) const STRINGS: Strings = Strings {
+    window_title: "Claude Code 사용량 모니터",
+    refresh: "새로고침",
+    update_frequency: "업데이트 주기",
+    one_minute: "1분",
+    five_minutes: "5분",
+    fifteen_minutes: "15분",
+    one_hour: "1시간",
+    settings: "설정",
+    start_with_windows: "Windows 시작 시 자동 실행",
+    reset_position: "위치 초기화",
+    language: "언어",
+    system_default: "시스템 기본값",
+    check_for_updates: "업데이트 확인",
+    checking_for_updates: "업데이트 확인 중...",
+    updates: "업데이트",
+    update_in_progress: "이미 업데이트 확인이 진행 중입니다.",
+    up_to_date: "이미 최신 버전입니다.",
+    up_to_date_short: "최신",
+    update_failed: "자동 업데이트를 완료할 수 없습니다",
+    applying_update: "업데이트 적용 중...",
+    update_to: "업데이트 대상",
+    update_available: "업데이트 사용 가능",
+    update_prompt_now: "버전 {version}을 사용할 수 있습니다. 지금 업데이트하시겠습니까?",
+    exit: "종료",
+    session_window: "5h",
+    weekly_window: "7d",
+    now: "지금",
+    day_suffix: "일",
+    hour_suffix: "시간",
+    minute_suffix: "분",
+    second_suffix: "초",
+};

src/localization/mod.rs

@@ -2,6 +2,7 @@ mod english;
 mod french;
 mod german;
 mod japanese;
+mod korean;
 mod spanish;
 
 use windows::core::PWSTR;
@@ -17,15 +18,17 @@ pub enum LanguageId {
     French,
     German,
     Japanese,
+    Korean,
 }
 
 impl LanguageId {
-    pub const ALL: [LanguageId; 5] = [
+    pub const ALL: [LanguageId; 6] = [
         LanguageId::English,
         LanguageId::Spanish,
         LanguageId::French,
         LanguageId::German,
         LanguageId::Japanese,
+        LanguageId::Korean,
     ];
 
     pub fn code(self) -> &'static str {
@@ -35,6 +38,7 @@ impl LanguageId {
             Self::French => "fr",
             Self::German => "de",
             Self::Japanese => "ja",
+            Self::Korean => "ko",
         }
     }
 
@@ -45,6 +49,7 @@ impl LanguageId {
             Self::French => "Français",
             Self::German => "Deutsch",
             Self::Japanese => "日本語",
+            Self::Korean => "한국어",
         }
     }
 
@@ -55,6 +60,7 @@ impl LanguageId {
             Self::French => french::STRINGS,
             Self::German => german::STRINGS,
             Self::Japanese => japanese::STRINGS,
+            Self::Korean => korean::STRINGS,
         }
     }
 
@@ -65,6 +71,7 @@ impl LanguageId {
             Self::French => french::UPDATE_VIA_WINGET_LABEL,
             Self::German => german::UPDATE_VIA_WINGET_LABEL,
             Self::Japanese => japanese::UPDATE_VIA_WINGET_LABEL,
+            Self::Korean => korean::UPDATE_VIA_WINGET_LABEL,
         }
     }
 
@@ -80,6 +87,7 @@ impl LanguageId {
             "fr" => Some(Self::French),
             "de" => Some(Self::German),
             "ja" => Some(Self::Japanese),
+            "ko" => Some(Self::Korean),
             _ => None,
         }
     }

src/window.rs

@@ -106,6 +106,7 @@ const IDM_LANG_SPANISH: u16 = 42;
 const IDM_LANG_FRENCH: u16 = 43;
 const IDM_LANG_GERMAN: u16 = 44;
 const IDM_LANG_JAPANESE: u16 = 45;
+const IDM_LANG_KOREAN: u16 = 46;
 
 const DIVIDER_HIT_ZONE: i32 = 13; // LEFT_DIVIDER_W + DIVIDER_RIGHT_MARGIN
 
@@ -1817,7 +1818,7 @@ unsafe extern "system" fn wnd_proc(
                     SetTimer(hwnd, TIMER_POLL, new_interval, None);
                 }
                 IDM_LANG_SYSTEM | IDM_LANG_ENGLISH | IDM_LANG_SPANISH | IDM_LANG_FRENCH
-                | IDM_LANG_GERMAN | IDM_LANG_JAPANESE => {
+                | IDM_LANG_GERMAN | IDM_LANG_JAPANESE | IDM_LANG_KOREAN => {
                     let language_override = match id {
                         IDM_LANG_SYSTEM => None,
                         IDM_LANG_ENGLISH => Some(LanguageId::English),
@@ -1825,6 +1826,7 @@ unsafe extern "system" fn wnd_proc(
                         IDM_LANG_FRENCH => Some(LanguageId::French),
                         IDM_LANG_GERMAN => Some(LanguageId::German),
                         IDM_LANG_JAPANESE => Some(LanguageId::Japanese),
+                        IDM_LANG_KOREAN => Some(LanguageId::Korean),
                         _ => None,
                     };
                     {
@@ -1991,6 +1993,7 @@ fn show_context_menu(hwnd: HWND) {
                 LanguageId::French => IDM_LANG_FRENCH,
                 LanguageId::German => IDM_LANG_GERMAN,
                 LanguageId::Japanese => IDM_LANG_JAPANESE,
+                LanguageId::Korean => IDM_LANG_KOREAN,
             };
             let label_str = native_interop::wide_str(language.native_name());
             let flags = if language_override == Some(language) {