Fix: Convert numpy types to prevent Gradio slider error

A `TypeError` occurred when running the synthesizer a second time after using the "Auto-Recommend (Analyze MIDI)" feature.

app.py

@@ -1614,7 +1614,13 @@ def process_and_render_file(input_file, *args, progress=gr.Progress()):
 
     # Always update all 13 controls to match the final parameters used in the backend
     for key in s8bit_control_keys:
-        final_ui_updates.append(getattr(final_params, key))
+        value = getattr(final_params, key)
+        # Explicitly convert numpy numeric types to native Python types.
+        # This prevents them from being serialized as strings in the UI,
+        # which would cause a TypeError on the next run.
+        if isinstance(value, np.generic):
+            value = value.item()
+        final_ui_updates.append(value)
 
     # Format the main results for the output components
     main_results = [