fix: ensure initial scaling plot uses Pareto frontier by default

The initial plot was generated with use_pareto=False even though
the UI radio button defaults to "Fit Pareto Frontier" (value=True).
This caused a mismatch between the UI selection and the displayed plot.

app.py

@@ -1272,7 +1272,7 @@ if __name__ == "__main__":
                         )
 
                     with gr.Column(scale=3):
-                        initial_scaling_fig = create_scaling_plot(data_manager, last_period) if last_period else go.Figure()
+                        initial_scaling_fig = create_scaling_plot(data_manager, last_period, use_pareto=True) if last_period else go.Figure()
                         scaling_plot = gr.Plot(initial_scaling_fig)
 
                 def update_scaling_mode_visibility(mode):