fixup: wrong metadata key

src/main.py

@@ -135,7 +135,7 @@ async def process_transaction(
             db=db,
             transaction=transaction,
             fraud_score=fraud_output.fraud_probability,
-            model_version=fraud_output.model_metadata['model_version'] if 'model_version' in fraud_output.model_metadata else 'unknown'
+            model_version=fraud_output.model_metadata['version'] if 'version' in fraud_output.model_metadata else 'unknown'
         )
 
         # Send notification to the user