feat: Integrate IndexTTS2 model and update related schemas and frontend components

qwen3-tts-backend/db/crud.py

@@ -564,6 +564,7 @@ def update_audiobook_character(
     description: Optional[str] = None,
     instruct: Optional[str] = None,
     voice_design_id: Optional[int] = None,
+    use_indextts2: Optional[bool] = None,
 ) -> Optional[AudiobookCharacter]:
     char = db.query(AudiobookCharacter).filter(AudiobookCharacter.id == char_id).first()
     if not char:
@@ -578,6 +579,8 @@ def update_audiobook_character(
         char.instruct = instruct
     if voice_design_id is not None:
         char.voice_design_id = voice_design_id
+    if use_indextts2 is not None:
+        char.use_indextts2 = use_indextts2
     db.commit()
     db.refresh(char)
     return char