Fix warmup_gsa: handle multi-element _gsa_buf (Nvfp4GroupedLinear per-group gsa)

single_shot_inference.py

@@ -1886,7 +1886,8 @@ def main():
                 if pl is None: continue
                 for key, lin in pl.items():
                     if hasattr(lin, '_gsa_buf') and hasattr(lin, '_use_runtime_gsa') and lin._use_runtime_gsa:
-                        fixed_gsa = lin._gsa_buf.item()  # One-time sync
+                        # Nvfp4GroupedLinear has per-group gsa; reduce to scalar (max) for fixed gsa
+                        fixed_gsa = lin._gsa_buf.max().item() if lin._gsa_buf.numel() > 1 else lin._gsa_buf.item()
                         lin._activation_global_scale = fixed_gsa
                         lin._use_runtime_gsa = False
                         n_fixed += 1