fix: use pytchat interruptable=False for thread safety

app.py

@@ -108,7 +108,7 @@ def _scraper_thread_fn(video_id: str, redis_key: str, stop_event: threading.Even
 
     logger.info("Scraper thread starting — video=%s key=%s", video_id, redis_key)
     try:
-        chat = pytchat.create(video_id=video_id)
+        chat = pytchat.create(video_id=video_id, interruptable=False)
     except Exception as exc:
         logger.error("pytchat.create failed: %s", exc)
         return