feat: add Catalan (ca) language support as default locale

app/api/generate/scene-content/route.ts

@@ -69,7 +69,7 @@ export async function POST(req: NextRequest) {
     // Ensure outline has language from stageInfo (fallback for older outlines)
     const outline: SceneOutline = {
       ...rawOutline,
-      language: rawOutline.language || (stageInfo?.language as 'zh-CN' | 'en-US') || 'zh-CN',
+      language: rawOutline.language || (stageInfo?.language as 'zh-CN' | 'en-US' | 'ca') || 'zh-CN',
     };
 
     // ── Model resolution from request headers ──

app/page.tsx

@@ -57,14 +57,14 @@ const RECENT_OPEN_STORAGE_KEY = 'recentClassroomsOpen';
 interface FormState {
   pdfFile: File | null;
   requirement: string;
-  language: 'zh-CN' | 'en-US';
+  language: 'zh-CN' | 'en-US' | 'ca';
   webSearch: boolean;
 }
 
 const initialFormState: FormState = {
   pdfFile: null,
   requirement: '',
-  language: 'zh-CN',
+  language: 'ca',
   webSearch: false,
 };
 
@@ -100,10 +100,11 @@ function HomePage() {
       const savedLanguage = localStorage.getItem(LANGUAGE_STORAGE_KEY);
       const updates: Partial<FormState> = {};
       if (savedWebSearch === 'true') updates.webSearch = true;
-      if (savedLanguage === 'zh-CN' || savedLanguage === 'en-US') {
+      if (savedLanguage === 'zh-CN' || savedLanguage === 'en-US' || savedLanguage === 'ca') {
         updates.language = savedLanguage;
       } else {
-        const detected = navigator.language?.startsWith('zh') ? 'zh-CN' : 'en-US';
+        const lang = navigator.language ?? '';
+        const detected: 'zh-CN' | 'en-US' | 'ca' = lang.startsWith('zh') ? 'zh-CN' : lang.startsWith('ca') ? 'ca' : 'en-US';
         updates.language = detected;
       }
       if (Object.keys(updates).length > 0) {
@@ -346,7 +347,7 @@ function HomePage() {
             }}
             className="flex items-center gap-1 px-3 py-1.5 rounded-full text-xs font-bold text-gray-500 dark:text-gray-400 hover:bg-white dark:hover:bg-gray-700 hover:text-gray-800 dark:hover:text-gray-200 hover:shadow-sm transition-all"
           >
-            {locale === 'zh-CN' ? 'CN' : 'EN'}
+            {{ 'zh-CN': 'CN', 'en-US': 'EN', 'ca': 'CA' }[locale] ?? 'EN'}
           </button>
           {languageOpen && (
             <div className="absolute top-full mt-2 right-0 bg-white dark:bg-gray-800 border border-gray-200 dark:border-gray-700 rounded-lg shadow-lg overflow-hidden z-50 min-w-[120px]">
@@ -376,6 +377,19 @@ function HomePage() {
               >
                 English
               </button>
+              <button
+                onClick={() => {
+                  setLocale('ca');
+                  setLanguageOpen(false);
+                }}
+                className={cn(
+                  'w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors',
+                  locale === 'ca' &&
+                    'bg-purple-50 dark:bg-purple-900/20 text-purple-600 dark:text-purple-400',
+                )}
+              >
+                Català
+              </button>
             </div>
           )}
         </div>

components/agent/agent-bar.tsx

@@ -83,7 +83,10 @@ function AgentVoicePill({
       const courseLanguage =
         (typeof localStorage !== 'undefined' && localStorage.getItem('generationLanguage')) ||
         'zh-CN';
-      const previewText = courseLanguage === 'en-US' ? 'Welcome to AI Classroom' : '欢迎来到AI课堂';
+      const previewText =
+        courseLanguage === 'zh-CN' ? '欢迎来到AI课堂' :
+        courseLanguage === 'ca' ? "Benvingut a l'aula d'IA" :
+        'Welcome to AI Classroom';
 
       if (providerId === 'browser-native-tts') {
         const { promise, cancel } = playBrowserTTSPreview({ text: previewText, voice: voiceId });
@@ -308,7 +311,10 @@ function TeacherVoicePill({
       const courseLanguage =
         (typeof localStorage !== 'undefined' && localStorage.getItem('generationLanguage')) ||
         'zh-CN';
-      const previewText = courseLanguage === 'en-US' ? 'Welcome to AI Classroom' : '欢迎来到AI课堂';
+      const previewText =
+        courseLanguage === 'zh-CN' ? '欢迎来到AI课堂' :
+        courseLanguage === 'ca' ? "Benvingut a l'aula d'IA" :
+        'Welcome to AI Classroom';
 
       if (providerId === 'browser-native-tts') {
         const { promise, cancel } = playBrowserTTSPreview({ text: previewText, voice: voiceId });

components/generation/generation-toolbar.tsx

@@ -28,8 +28,8 @@ const MAX_PDF_SIZE_BYTES = MAX_PDF_SIZE_MB * 1024 * 1024;
 
 // ─── Types ───────────────────────────────────────────────────
 export interface GenerationToolbarProps {
-  language: 'zh-CN' | 'en-US';
-  onLanguageChange: (lang: 'zh-CN' | 'en-US') => void;
+  language: 'zh-CN' | 'en-US' | 'ca';
+  onLanguageChange: (lang: 'zh-CN' | 'en-US' | 'ca') => void;
   webSearch: boolean;
   onWebSearchChange: (v: boolean) => void;
   onSettingsOpen: (section?: SettingsSection) => void;
@@ -361,11 +361,15 @@ export function GenerationToolbar({
       <Tooltip>
         <TooltipTrigger asChild>
           <button
-            onClick={() => onLanguageChange(language === 'zh-CN' ? 'en-US' : 'zh-CN')}
+            onClick={() => {
+              const LANGS = ['zh-CN', 'en-US', 'ca'] as const;
+              const nextLang = LANGS[(LANGS.indexOf(language) + 1) % 3];
+              onLanguageChange(nextLang);
+            }}
             className={pillMuted}
           >
             <Globe className="size-3.5" />
-            <span>{language === 'zh-CN' ? '中文' : 'EN'}</span>
+            <span>{{ 'zh-CN': '中文', 'en-US': 'EN', 'ca': 'CA' }[language]}</span>
           </button>
         </TooltipTrigger>
         <TooltipContent>{t('toolbar.languageHint')}</TooltipContent>

components/header.tsx

@@ -108,7 +108,7 @@ export function Header({ currentSceneTitle }: HeaderProps) {
               }}
               className="flex items-center gap-1 px-3 py-1.5 rounded-full text-xs font-bold text-gray-500 dark:text-gray-400 hover:bg-white dark:hover:bg-gray-700 hover:text-gray-800 dark:hover:text-gray-200 hover:shadow-sm transition-all"
             >
-              {locale === 'zh-CN' ? 'CN' : 'EN'}
+              {{ 'zh-CN': 'CN', 'en-US': 'EN', 'ca': 'CA' }[locale] ?? 'EN'}
             </button>
             {languageOpen && (
               <div className="absolute top-full mt-2 right-0 bg-white dark:bg-gray-800 border border-gray-200 dark:border-gray-700 rounded-lg shadow-lg overflow-hidden z-50 min-w-[120px]">
@@ -138,6 +138,19 @@ export function Header({ currentSceneTitle }: HeaderProps) {
                 >
                   English
                 </button>
+                <button
+                  onClick={() => {
+                    setLocale('ca');
+                    setLanguageOpen(false);
+                  }}
+                  className={cn(
+                    'w-full px-4 py-2 text-left text-sm hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors',
+                    locale === 'ca' &&
+                      'bg-purple-50 dark:bg-purple-900/20 text-purple-600 dark:text-purple-400',
+                  )}
+                >
+                  Català
+                </button>
               </div>
             )}
           </div>

lib/audio/constants.ts

@@ -204,6 +204,8 @@ export const TTS_PROVIDERS: Record<TTSProviderId, TTSProviderConfig> = {
         gender: 'female',
       },
       { id: 'en-US-GuyNeural', name: 'Guy', language: 'en-US', gender: 'male' },
+      { id: 'ca-ES-AlbaNeural', name: 'Alba (Català)', language: 'ca-ES', gender: 'female' },
+      { id: 'ca-ES-EnricNeural', name: 'Enric (Català)', language: 'ca-ES', gender: 'male' },
     ],
     supportedFormats: ['mp3', 'wav', 'ogg'],
     speedRange: { min: 0.5, max: 2.0, default: 1.0 },

lib/generation/scene-generator.ts

@@ -735,7 +735,7 @@ function normalizeQuizAnswer(question: Record<string, unknown>): string[] | unde
 async function generateInteractiveContent(
   outline: SceneOutline,
   aiCall: AICallFn,
-  language: 'zh-CN' | 'en-US' = 'zh-CN',
+  language: 'zh-CN' | 'en-US' | 'ca' = 'zh-CN',
 ): Promise<GeneratedInteractiveContent | null> {
   const config = outline.interactiveConfig!;
 

lib/hooks/use-i18n.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import { createContext, useContext, useState, useEffect, ReactNode } from 'react';
-import { Locale, translate, defaultLocale } from '@/lib/i18n';
+import { Locale, translate, defaultLocale, VALID_LOCALES } from '@/lib/i18n';
 
 type I18nContextType = {
   locale: Locale;
@@ -10,7 +10,6 @@ type I18nContextType = {
 };
 
 const LOCALE_STORAGE_KEY = 'locale';
-const VALID_LOCALES: Locale[] = ['zh-CN', 'en-US'];
 
 const I18nContext = createContext<I18nContextType | undefined>(undefined);
 
@@ -26,7 +25,8 @@ export function I18nProvider({ children }: { children: ReactNode }) {
         setLocaleState(stored as Locale);
         return;
       }
-      const detected = navigator.language?.startsWith('zh') ? 'zh-CN' : 'en-US';
+      const lang = navigator.language ?? '';
+      const detected: Locale = lang.startsWith('zh') ? 'zh-CN' : lang.startsWith('ca') ? 'ca' : 'en-US';
       localStorage.setItem(LOCALE_STORAGE_KEY, detected);
       setLocaleState(detected);
     } catch {

lib/i18n/chat.ts

@@ -72,6 +72,80 @@ export const chatZhCN = {
   },
 } as const;
 
+export const chatCa = {
+  chat: {
+    lecture: 'Lliçó',
+    noConversations: 'Cap conversa',
+    startConversation: 'Escriu un missatge per començar a xatejar',
+    noMessages: 'Encara no hi ha missatges',
+    ended: 'finalitzat',
+    unknown: 'Desconegut',
+    stopDiscussion: 'Aturar discussió',
+    endQA: 'Finalitzar P&R',
+    tabs: {
+      lecture: 'Notes',
+      chat: 'Xat',
+    },
+    lectureNotes: {
+      empty: 'Les notes apareixeran aquí després de la reproducció de la lliçó',
+      emptyHint: 'Premeu reproduir per iniciar la lliçó',
+      pageLabel: 'Pàgina {n}',
+      currentPage: 'Actual',
+    },
+    badge: {
+      qa: 'P&R',
+      discussion: 'DISC',
+      lecture: 'LLIÇ',
+    },
+  },
+  actions: {
+    names: {
+      spotlight: 'Focus',
+      laser: 'Làser',
+      wb_open: 'Obrir pissarra',
+      wb_draw_text: 'Text a la pissarra',
+      wb_draw_shape: 'Forma a la pissarra',
+      wb_draw_chart: 'Gràfic a la pissarra',
+      wb_draw_latex: 'Fórmula a la pissarra',
+      wb_draw_table: 'Taula a la pissarra',
+      wb_draw_line: 'Línia a la pissarra',
+      wb_clear: 'Netejar pissarra',
+      wb_delete: 'Eliminar element',
+      wb_close: 'Tancar pissarra',
+      discussion: 'Discussió',
+    },
+    status: {
+      inputStreaming: 'En espera',
+      inputAvailable: 'Executant',
+      outputAvailable: 'Completat',
+      outputError: 'Error',
+      outputDenied: 'Denegat',
+      running: 'Executant',
+      result: 'Completat',
+      error: 'Error',
+    },
+  },
+  agentBar: {
+    readyToLearn: 'Preparats per aprendre junts?',
+    expandedTitle: 'Configuració de rols de l\'aula',
+    configTooltip: 'Clic per configurar els rols de l\'aula',
+    voiceLabel: 'Veu',
+    voiceLoading: 'Carregant...',
+    voiceAutoAssign: 'Les veus s\'assignaran automàticament',
+  },
+  proactiveCard: {
+    discussion: 'Discussió',
+    join: 'Unir-se',
+    skip: 'Ometre',
+    pause: 'Pausar',
+    resume: 'Reprendre',
+  },
+  voice: {
+    startListening: 'Entrada de veu',
+    stopListening: 'Aturar gravació',
+  },
+} as const;
+
 export const chatEnUS = {
   chat: {
     lecture: 'Lecture',

lib/i18n/common.ts

@@ -39,6 +39,47 @@ export const commonZhCN = {
   },
 } as const;
 
+export const commonCa = {
+  common: {
+    you: 'Tu',
+    confirm: 'Confirmar',
+    cancel: 'Cancel·lar',
+    loading: 'Carregant...',
+  },
+  home: {
+    slogan: 'Aprenentatge Generatiu en Aula Interactiva Multi-Agent',
+    greeting: 'Hola, ',
+  },
+  toolbar: {
+    languageHint: 'El curs es generarà en aquesta llengua',
+    pdfParser: 'Analitzador',
+    pdfUpload: 'Pujar PDF',
+    removePdf: 'Eliminar fitxer',
+    webSearchOn: 'Activat',
+    webSearchOff: 'Clic per activar',
+    webSearchDesc: 'Cerca informació actualitzada a la web abans de la generació',
+    webSearchProvider: 'Motor de cerca',
+    webSearchNoProvider: 'Configura la clau API de cerca a la Configuració',
+    selectProvider: 'Selecciona proveïdor',
+    configureProvider: 'Configura model',
+    configureProviderHint: 'Configura almenys un proveïdor de model per generar cursos',
+    enterClassroom: 'Entrar a l\'aula',
+    advancedSettings: 'Configuració avançada',
+    ttsTitle: 'Síntesi de veu',
+    ttsHint: 'Trieu una veu per al professor IA',
+    ttsPreview: 'Previsualitzar',
+    ttsPreviewing: 'Reproduint...',
+  },
+  export: {
+    pptx: 'Exportar PPTX',
+    resourcePack: 'Exportar paquet de recursos',
+    resourcePackDesc: 'PPTX + pàgines interactives',
+    exporting: 'Exportant...',
+    exportSuccess: 'Exportació correcta',
+    exportFailed: 'Error en l\'exportació',
+  },
+} as const;
+
 export const commonEnUS = {
   common: {
     you: 'You',