[Feature] Enable return routed experts (#12162)

Co-authored-by: yizhang2077 <1109276519@qq.com>
Co-authored-by: Liangsheng Yin <lsyincs@gmail.com>

python/sglang/srt/server_args.py

@@ -573,6 +573,7 @@ class ServerArgs:
     disable_fast_image_processor: bool = False
     keep_mm_feature_on_device: bool = False
     enable_return_hidden_states: bool = False
+    enable_return_routed_experts: bool = False
     scheduler_recv_interval: int = 1
     numa_node: Optional[List[int]] = None
     enable_deterministic_inference: bool = False
@@ -4101,6 +4102,11 @@ class ServerArgs:
             action="store_true",
             help="Enable returning hidden states with responses.",
         )
+        parser.add_argument(
+            "--enable-return-routed-experts",
+            action="store_true",
+            help="Enable returning routed experts of each layer with responses.",
+        )
         parser.add_argument(
             "--scheduler-recv-interval",
             type=int,