feat: add user preferences migration and context

qwen3-tts-frontend/src/components/tts/VoiceCloneForm.tsx

@@ -16,6 +16,7 @@ import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from '@/comp
 import { ttsApi, jobApi } from '@/lib/api'
 import { useJobPolling } from '@/hooks/useJobPolling'
 import { useHistoryContext } from '@/contexts/HistoryContext'
+import { useUserPreferences } from '@/contexts/UserPreferencesContext'
 import { LoadingState } from '@/components/LoadingState'
 import { AudioPlayer } from '@/components/AudioPlayer'
 import { FileUploader } from '@/components/FileUploader'
@@ -54,6 +55,7 @@ function VoiceCloneForm() {
 
   const { currentJob, isPolling, isCompleted, startPolling, elapsedTime } = useJobPolling()
   const { refresh } = useHistoryContext()
+  const { preferences } = useUserPreferences()
 
   const {
     register,
@@ -76,10 +78,16 @@ function VoiceCloneForm() {
       top_k: 20,
       top_p: 0.7,
       repetition_penalty: 1.05,
-      backend: 'local',
+      backend: preferences?.default_backend || 'local',
     } as Partial<FormData>,
   })
 
+  useEffect(() => {
+    if (preferences?.default_backend) {
+      setValue('backend', preferences.default_backend)
+    }
+  }, [preferences?.default_backend, setValue])
+
   useEffect(() => {
     const fetchData = async () => {
       try {