Update app.py

app.py

@@ -568,7 +568,7 @@ async def run_tts_pipeline(task_id: str, story: StoryCreationDTO):
         tasks[task_id] = {
             "status": "completed",
             "result": {
-                "fileName": os.path.basename(final_generated_story_path),
+                "fileName": os.path.basename(mp3_path),
                 "duration": duration_seconds,
                 "audioPath": audio_url
             }