Update app.py

fixing grad minor bug

app.py

@@ -121,7 +121,7 @@ def simple_generative_inference(image, mode, model, n_iterations=10, step_size=0
         image_tensor = image_tensor + step_size * grad
         delta = image_tensor - image_original
         delta = torch.clamp(delta, -eps, eps)   # Keep within range
-        image_tensor = torch.clamp(image_original + diff, 0, 1)
+        image_tensor = torch.clamp(image_original + delta, 0, 1)
         image_tensor = image_tensor.clone().detach().requires_grad_(True)  # Ensure it's a new leaf tensor
         image_tensor.retain_grad()