fix: use weights_only=True for safe PyTorch model loading

Replace unsafe `torch.load(path)` with `torch.load(path,
map_location=self.device, weights_only=True)` to prevent
pickle deserialization RCE (trailofbits.python.pickles-in-pytorch).

weights_only=True disables pickle entirely for model loading,
which is the PyTorch-recommended mitigation (available since 1.13).
Also adds map_location for correct CPU/GPU device mapping.

Closes #106

Co-Authored-By: claude-flow <ruv@ruv.net>

references/wifi_densepose_pytorch.py

@@ -441,7 +441,7 @@ class WiFiDensePoseTrainer:
         }, path)
     
     def load_model(self, path):
-        checkpoint = torch.load(path)
+        checkpoint = torch.load(path, map_location=self.device, weights_only=True)
         self.model.load_state_dict(checkpoint['model_state_dict'])
         self.optimizer.load_state_dict(checkpoint['optimizer_state_dict'])