Use dtype instead of deprecated torch_dtype in model_kwargs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

models/medgemma_agent.py

@@ -229,7 +229,7 @@ class MedGemmaAgent:
             self._print("Using CPU")
 
         model_kwargs = dict(
-            torch_dtype=torch.bfloat16 if device != "cpu" else torch.float32,
+            dtype=torch.bfloat16 if device != "cpu" else torch.float32,
             device_map="auto",
         )