fix: rollback generation_config to safe Qwen2.5 defaults (rep_penalty 1.3→1.1)

generation_config.json

@@ -6,9 +6,9 @@
     151643
   ],
   "pad_token_id": 151643,
-  "repetition_penalty": 1.3,
+  "repetition_penalty": 1.1,
   "temperature": 0.7,
-  "top_k": 50,
-  "top_p": 0.92,
+  "top_k": 20,
+  "top_p": 0.8,
   "transformers_version": "4.57.6"
 }