Update ui_helpers.py

ui_helpers.py

@@ -23,7 +23,7 @@ def get_model_display_name(model_name: str) -> str:
 
 def select_random_models() -> tuple[str, str]:
     """Randomly select two models from the available list including gpt5."""
-    models = ["gemini", "gemini", "gemini", "gemini"]
+    models = ["mistral", "mistral", "mistral", "mistral"]
     selected_models = random.sample(models, 2)
     return selected_models[0], selected_models[1]