feat: add Chatterbox Turbo engine and per-engine language lists

- New ChatterboxTurboTTSBackend wrapping ChatterboxTurboTTS (ResembleAI/chatterbox-turbo)
- English-only 350M model with paralinguistic tag support ([laugh], [cough], [chuckle])
- Bypasses upstream token=True bug by calling snapshot_download(token=None) + from_local()
- Same CPU-on-macOS forcing and torch.load monkey-patching as multilingual backend
- Full engine integration: generate, stream, model status/download/delete endpoints
- Language dropdown now shows only languages supported by the selected engine
- Per-engine language maps: Qwen (10), LuxTTS (en), Chatterbox (23), Turbo (en)
- Auto-switches to English when selecting English-only engines
- Backend language regex expanded to accept all 23 Chatterbox languages

app/src/components/Generation/FloatingGenerateBox.tsx

@@ -13,7 +13,7 @@ import {
 } from '@/components/ui/select';
 import { Textarea } from '@/components/ui/textarea';
 import { useToast } from '@/components/ui/use-toast';
-import { LANGUAGE_OPTIONS } from '@/lib/constants/languages';
+import { getLanguageOptionsForEngine } from '@/lib/constants/languages';
 import { useGenerationForm } from '@/lib/hooks/useGenerationForm';
 import { useProfile, useProfiles } from '@/lib/hooks/useProfiles';
 import { useAddStoryItem, useStory } from '@/lib/hooks/useStories';
@@ -381,25 +381,30 @@ export function FloatingGenerateBox({
                   <FormField
                     control={form.control}
                     name="language"
-                    render={({ field }) => (
-                      <FormItem className="flex-1 space-y-0">
-                        <Select onValueChange={field.onChange} defaultValue={field.value}>
-                          <FormControl>
-                            <SelectTrigger className="h-8 text-xs bg-card border-border rounded-full hover:bg-background/50 transition-all">
-                              <SelectValue />
-                            </SelectTrigger>
-                          </FormControl>
-                          <SelectContent>
-                            {LANGUAGE_OPTIONS.map((lang) => (
-                              <SelectItem key={lang.value} value={lang.value} className="text-xs">
-                                {lang.label}
-                              </SelectItem>
-                            ))}
-                          </SelectContent>
-                        </Select>
-                        <FormMessage className="text-xs" />
-                      </FormItem>
-                    )}
+                    render={({ field }) => {
+                      const engineLangs = getLanguageOptionsForEngine(
+                        form.watch('engine') || 'qwen',
+                      );
+                      return (
+                        <FormItem className="flex-1 space-y-0">
+                          <Select onValueChange={field.onChange} value={field.value}>
+                            <FormControl>
+                              <SelectTrigger className="h-8 text-xs bg-card border-border rounded-full hover:bg-background/50 transition-all">
+                                <SelectValue />
+                              </SelectTrigger>
+                            </FormControl>
+                            <SelectContent>
+                              {engineLangs.map((lang) => (
+                                <SelectItem key={lang.value} value={lang.value} className="text-xs">
+                                  {lang.label}
+                                </SelectItem>
+                              ))}
+                            </SelectContent>
+                          </Select>
+                          <FormMessage className="text-xs" />
+                        </FormItem>
+                      );
+                    }}
                   />
 
                   <FormItem className="flex-1 space-y-0">
@@ -409,13 +414,19 @@ export function FloatingGenerateBox({
                           ? 'luxtts'
                           : form.watch('engine') === 'chatterbox'
                             ? 'chatterbox'
-                            : `qwen:${form.watch('modelSize') || '1.7B'}`
+                            : form.watch('engine') === 'chatterbox_turbo'
+                              ? 'chatterbox_turbo'
+                              : `qwen:${form.watch('modelSize') || '1.7B'}`
                       }
                       onValueChange={(value) => {
                         if (value === 'luxtts') {
                           form.setValue('engine', 'luxtts');
+                          form.setValue('language', 'en');
                         } else if (value === 'chatterbox') {
                           form.setValue('engine', 'chatterbox');
+                        } else if (value === 'chatterbox_turbo') {
+                          form.setValue('engine', 'chatterbox_turbo');
+                          form.setValue('language', 'en');
                         } else {
                           const [, modelSize] = value.split(':');
                           form.setValue('engine', 'qwen');
@@ -441,6 +452,12 @@ export function FloatingGenerateBox({
                         <SelectItem value="chatterbox" className="text-xs text-muted-foreground">
                           Chatterbox
                         </SelectItem>
+                        <SelectItem
+                          value="chatterbox_turbo"
+                          className="text-xs text-muted-foreground"
+                        >
+                          Chatterbox Turbo
+                        </SelectItem>
                       </SelectContent>
                     </Select>
                   </FormItem>

app/src/components/Generation/GenerationForm.tsx

@@ -19,7 +19,7 @@ import {
   SelectValue,
 } from '@/components/ui/select';
 import { Textarea } from '@/components/ui/textarea';
-import { LANGUAGE_OPTIONS } from '@/lib/constants/languages';
+import { getLanguageOptionsForEngine } from '@/lib/constants/languages';
 import { useGenerationForm } from '@/lib/hooks/useGenerationForm';
 import { useProfile } from '@/lib/hooks/useProfiles';
 import { useUIStore } from '@/stores/uiStore';
@@ -109,13 +109,19 @@ export function GenerationForm() {
                       ? 'luxtts'
                       : form.watch('engine') === 'chatterbox'
                         ? 'chatterbox'
-                        : `qwen:${form.watch('modelSize') || '1.7B'}`
+                        : form.watch('engine') === 'chatterbox_turbo'
+                          ? 'chatterbox_turbo'
+                          : `qwen:${form.watch('modelSize') || '1.7B'}`
                   }
                   onValueChange={(value) => {
                     if (value === 'luxtts') {
                       form.setValue('engine', 'luxtts');
+                      form.setValue('language', 'en');
                     } else if (value === 'chatterbox') {
                       form.setValue('engine', 'chatterbox');
+                    } else if (value === 'chatterbox_turbo') {
+                      form.setValue('engine', 'chatterbox_turbo');
+                      form.setValue('language', 'en');
                     } else {
                       const [, modelSize] = value.split(':');
                       form.setValue('engine', 'qwen');
@@ -133,40 +139,46 @@ export function GenerationForm() {
                     <SelectItem value="qwen:0.6B">Qwen3-TTS 0.6B</SelectItem>
                     <SelectItem value="luxtts">LuxTTS</SelectItem>
                     <SelectItem value="chatterbox">Chatterbox</SelectItem>
+                    <SelectItem value="chatterbox_turbo">Chatterbox Turbo</SelectItem>
                   </SelectContent>
                 </Select>
                 <FormDescription>
                   {form.watch('engine') === 'luxtts'
                     ? 'Fast, English-focused'
                     : form.watch('engine') === 'chatterbox'
-                      ? 'Multilingual, incl. Hebrew'
-                      : 'Multi-language, two sizes'}
+                      ? '23 languages, incl. Hebrew'
+                      : form.watch('engine') === 'chatterbox_turbo'
+                        ? 'English, [laugh] [cough] tags'
+                        : 'Multi-language, two sizes'}
                 </FormDescription>
               </FormItem>
 
               <FormField
                 control={form.control}
                 name="language"
-                render={({ field }) => (
-                  <FormItem>
-                    <FormLabel>Language</FormLabel>
-                    <Select onValueChange={field.onChange} defaultValue={field.value}>
-                      <FormControl>
-                        <SelectTrigger>
-                          <SelectValue />
-                        </SelectTrigger>
-                      </FormControl>
-                      <SelectContent>
-                        {LANGUAGE_OPTIONS.map((lang) => (
-                          <SelectItem key={lang.value} value={lang.value}>
-                            {lang.label}
-                          </SelectItem>
-                        ))}
-                      </SelectContent>
-                    </Select>
-                    <FormMessage />
-                  </FormItem>
-                )}
+                render={({ field }) => {
+                  const engineLangs = getLanguageOptionsForEngine(form.watch('engine') || 'qwen');
+                  return (
+                    <FormItem>
+                      <FormLabel>Language</FormLabel>
+                      <Select onValueChange={field.onChange} value={field.value}>
+                        <FormControl>
+                          <SelectTrigger>
+                            <SelectValue />
+                          </SelectTrigger>
+                        </FormControl>
+                        <SelectContent>
+                          {engineLangs.map((lang) => (
+                            <SelectItem key={lang.value} value={lang.value}>
+                              {lang.label}
+                            </SelectItem>
+                          ))}
+                        </SelectContent>
+                      </Select>
+                      <FormMessage />
+                    </FormItem>
+                  );
+                }}
               />
 
               <FormField

app/src/lib/api/types.ts

@@ -34,7 +34,7 @@ export interface GenerationRequest {
   language: LanguageCode;
   seed?: number;
   model_size?: '1.7B' | '0.6B';
-  engine?: 'qwen' | 'luxtts' | 'chatterbox';
+  engine?: 'qwen' | 'luxtts' | 'chatterbox' | 'chatterbox_turbo';
   instruct?: string;
 }
 

app/src/lib/constants/languages.ts

@@ -1,27 +1,86 @@
 /**
- * Supported languages for voice generation.
- * Most languages use Qwen3-TTS; Hebrew uses Chatterbox TTS.
+ * Supported languages for voice generation, per engine.
+ *
+ * Qwen3-TTS supports 10 languages.
+ * LuxTTS is English-only.
+ * Chatterbox Multilingual supports 23 languages.
+ * Chatterbox Turbo is English-only.
  */
 
-export const SUPPORTED_LANGUAGES = {
-  zh: 'Chinese',
+/** All languages that any engine supports. */
+export const ALL_LANGUAGES = {
+  ar: 'Arabic',
+  da: 'Danish',
+  de: 'German',
+  el: 'Greek',
   en: 'English',
+  es: 'Spanish',
+  fi: 'Finnish',
+  fr: 'French',
+  he: 'Hebrew',
+  hi: 'Hindi',
+  it: 'Italian',
   ja: 'Japanese',
   ko: 'Korean',
-  de: 'German',
-  fr: 'French',
-  ru: 'Russian',
+  ms: 'Malay',
+  nl: 'Dutch',
+  no: 'Norwegian',
+  pl: 'Polish',
   pt: 'Portuguese',
-  es: 'Spanish',
-  it: 'Italian',
-  he: 'Hebrew',
+  ru: 'Russian',
+  sv: 'Swedish',
+  sw: 'Swahili',
+  tr: 'Turkish',
+  zh: 'Chinese',
 } as const;
 
-export type LanguageCode = keyof typeof SUPPORTED_LANGUAGES;
+export type LanguageCode = keyof typeof ALL_LANGUAGES;
 
-export const LANGUAGE_CODES = Object.keys(SUPPORTED_LANGUAGES) as LanguageCode[];
+/** Per-engine supported language codes. */
+export const ENGINE_LANGUAGES: Record<string, readonly LanguageCode[]> = {
+  qwen: ['zh', 'en', 'ja', 'ko', 'de', 'fr', 'ru', 'pt', 'es', 'it'],
+  luxtts: ['en'],
+  chatterbox: [
+    'ar',
+    'da',
+    'de',
+    'el',
+    'en',
+    'es',
+    'fi',
+    'fr',
+    'he',
+    'hi',
+    'it',
+    'ja',
+    'ko',
+    'ms',
+    'nl',
+    'no',
+    'pl',
+    'pt',
+    'ru',
+    'sv',
+    'sw',
+    'tr',
+    'zh',
+  ],
+  chatterbox_turbo: ['en'],
+} as const;
 
+/** Helper: get language options for a given engine. */
+export function getLanguageOptionsForEngine(engine: string) {
+  const codes = ENGINE_LANGUAGES[engine] ?? ENGINE_LANGUAGES.qwen;
+  return codes.map((code) => ({
+    value: code,
+    label: ALL_LANGUAGES[code],
+  }));
+}
+
+// ── Backwards-compatible exports used elsewhere ──────────────────────
+export const SUPPORTED_LANGUAGES = ALL_LANGUAGES;
+export const LANGUAGE_CODES = Object.keys(ALL_LANGUAGES) as LanguageCode[];
 export const LANGUAGE_OPTIONS = LANGUAGE_CODES.map((code) => ({
   value: code,
-  label: SUPPORTED_LANGUAGES[code],
+  label: ALL_LANGUAGES[code],
 }));

app/src/lib/hooks/useGenerationForm.ts

@@ -16,7 +16,7 @@ const generationSchema = z.object({
   seed: z.number().int().optional(),
   modelSize: z.enum(['1.7B', '0.6B']).optional(),
   instruct: z.string().max(500).optional(),
-  engine: z.enum(['qwen', 'luxtts', 'chatterbox']).optional(),
+  engine: z.enum(['qwen', 'luxtts', 'chatterbox', 'chatterbox_turbo']).optional(),
 });
 
 export type GenerationFormValues = z.infer<typeof generationSchema>;
@@ -75,15 +75,19 @@ export function useGenerationForm(options: UseGenerationFormOptions = {}) {
           ? 'luxtts'
           : engine === 'chatterbox'
             ? 'chatterbox-tts'
-            : `qwen-tts-${data.modelSize}`;
+            : engine === 'chatterbox_turbo'
+              ? 'chatterbox-turbo'
+              : `qwen-tts-${data.modelSize}`;
       const displayName =
         engine === 'luxtts'
           ? 'LuxTTS'
           : engine === 'chatterbox'
             ? 'Chatterbox TTS'
-            : data.modelSize === '1.7B'
-              ? 'Qwen TTS 1.7B'
-              : 'Qwen TTS 0.6B';
+            : engine === 'chatterbox_turbo'
+              ? 'Chatterbox Turbo'
+              : data.modelSize === '1.7B'
+                ? 'Qwen TTS 1.7B'
+                : 'Qwen TTS 0.6B';
 
       try {
         const modelStatus = await apiClient.getModelStatus();