Update app.py

app.py

@@ -111,7 +111,7 @@ async def startup_event():
         miner_instance = ParallelMiner(num_cores=5)  # Increased cores for better performance
         # Start mining in background thread
         mining_instance = threading.Thread(
-            target=ParallelMiner(num_cores=5),
+            target=miner_instance,
             kwargs={"duration": None}  # Run forever
         )
         mining_instance.daemon = True