Update app.py

app.py

@@ -29,8 +29,8 @@ index.add(embeddings_np)
 # Load LLM (default Phi-4-mini)
 # -------------------------------
 model_choices = {
-    "openai/gpt-oss-120b": "microsoft/phi-4-mini",
-    "openai/gpt-oss-20b": "microsoft/phi-4-mini"  # placeholder, can map to another HF model
+    "openai/gpt-oss-120b": "microsoft/phi-2",
+    "openai/gpt-oss-20b": "microsoft/phi-2"  # placeholder, can map to another HF model
 }
 
 current_model_id = "openai/gpt-oss-120b"