refactor: Simplify TTS API endpoints by removing specific paths for generate and history

app/api/v1/tts.py

@@ -51,7 +51,7 @@ async def get_tts_service(
     return TTSService(session)
 
 
-@router.post("/generate")
+@router.post("")
 async def generate_tts(
     request: TTSGenerateRequest,
     current_user: Annotated[User, Depends(get_current_active_user_flexible)],
@@ -140,8 +140,8 @@ async def get_provider(
     )
 
 
-@router.get("/history")
-async def get_tts_history(
+@router.get("")
+async def get_tts_list(
     current_user: Annotated[User, Depends(get_current_active_user_flexible)],
     tts_service: Annotated[TTSService, Depends(get_tts_service)],
     limit: int = 50,