default rank 16 for faster CPU training

app.py

@@ -949,7 +949,7 @@ def gradio_main():
                         train_lr = gr.Number(label="Learning Rate", value=3e-4)
                         train_rank = gr.Slider(
                             label="Rank (r)", minimum=1, maximum=128,
-                            value=32, step=1,
+                            value=16, step=1,
                         )
 
                 # Button swap on click (separate handler, like rvc-beatrice)