fix: remove show_error from graph.launch() (Daggr/uvicorn do not support it)

app.py

@@ -123,5 +123,5 @@ graph = Graph(
     ],
 )
 
-# Launch the Space (show_error=True so node exceptions show the real message)
-graph.launch(show_error=True)
+# Launch the Space
+graph.launch()