Rm non-valid log on save_to_textbook_fs db.py

app/db.py

@@ -42,7 +42,7 @@ async def save_to_textbook_fs(doc_id: str, file_path: str):
         bucket = _get_textbook_fs()
         with open(file_path, "rb") as fp:
             await bucket.upload_from_stream(f"{doc_id}.pdf", fp)
-        logger.info(f"📦 textbook PDF stored → {TEXTBOOK_URI}/{bucket.database.name}")
+        logger.info(f"📦 textbook PDF stored for {doc_id} → {TEXTBOOK_URI}")
     except Exception as e:
         logger.warning(f"⚠️ textbook GridFS save failed: {e}")