feat(i18n): 설정 화면 하드코딩 문구를 I18n 키로 통일한다

SodaLive/Sources/Settings/Language/Models/LanguageOption.swift

@@ -15,10 +15,10 @@ enum LanguageOption: String, CaseIterable, Equatable {
 
     var displayName: String {
         switch self {
-        case .system: return String(localized: "시스템 기본")
-        case .ko:     return "한국어"
-        case .en:     return "English"
-        case .ja:     return "日本語"
+        case .system: return I18n.Settings.Language.systemDefault
+        case .ko:     return I18n.Settings.Language.korean
+        case .en:     return I18n.Settings.Language.english
+        case .ja:     return I18n.Settings.Language.japanese
         }
     }
 

SodaLive/Sources/Settings/Language/Views/LanguageSettingsView.swift

@@ -17,7 +17,7 @@ struct LanguageSettingsView: View {
             Color.black.ignoresSafeArea()
             
             VStack(spacing: 0) {
-                DetailNavigationBar(title: String(localized: "언어 설정"))
+                DetailNavigationBar(title: I18n.Settings.languageSettings)
                 
                 ScrollView(.vertical, showsIndicators: false) {
                     VStack(spacing: 0) {
@@ -58,7 +58,7 @@ struct LanguageSettingsView: View {
                         Button(action: {
                             Task { await viewModel.applyAndRestart() }
                         }) {
-                            Text("적용")
+                            Text(I18n.Settings.Language.apply)
                                 .appFont(size: 16, weight: .bold)
                                 .frame(width: cardWidth, height: 50)
                                 .background(Color.button)